@antarctica/bas-style-kit-pug-templates

A set of Pug templates implementing the BAS Style Kit.

Usage no npm install needed!

<script type="module">
  import antarcticaBasStyleKitPugTemplates from 'https://cdn.skypack.dev/@antarctica/bas-style-kit-pug-templates';
</script>

README

BAS Style Kit Pug Templates

A set of Pug templates implementing the BAS Style Kit.

Installation

NPM package

The recommended method to get these templates is through its NPM package, @antarctica/bas-style-kit-pug-templates.

Usage

Quickstart

Standard page

To create a page in an application or website based on the standard BAS page structure, create an application layout (e.g. layouts/app.pug) with the following:

extends ../node_modules/@antarctica/bas-style-kit-pug-templates/layouts/bas-style-kit/bsk--standard.pug

block append variables
  - attributes.site_title = 'Example service';
  - attributes.site_description = 'Service to act as an example';
  - bsk_attributes.site_nav_brand_text = 'Example service';
  - bsk_attributes.site_development_phase = 'beta';
  - bsk_attributes.site_feedback_href = '/feedback';
  - bsk_attributes.site_footer_policies_cookies_href = '/legal/cookies';
  - bsk_attributes.site_footer_policies_copyright_href = '/legal/copyright';
  - bsk_attributes.site_footer_policies_privacy_href = '/legal/privacy';
  //- Optional - add a custom CSS file with a relative URL
  - attributes.site_styles.push({href: '/css/app.css'});
  //- Optional - add a custom JS file with a SRI value
  - attributes.site_scripts.push({href: 'https://example.com/js/example.js', integrity: 'abc123'});
  //- Optional - enable Google Analaytics
  - attributes.site_analytics.id = '1234';
  //- Optional - choose between the `bsk-container` and `bsk-container-fluid` layout container
  - bsk_attributes.container_class = 'bsk-container';
  //- Optional - add navigation menu items
  - bsk_attributes.site_nav_primary.push({title: 'Item', href: '#'});
  - bsk_attributes.site_nav_secondary.push({title: 'Dropdown', items: [{title: 'Sub-item 1', href: '#'}]});
  - bsk_attributes.site_nav_launcher.push({title: 'Related service', href: 'https://example.com'});

Then create a specific page/view (e.g. view.pug) and place some content in the main_content block:

extends layouts/app.pug

block main_content
  header: h1 Example content
  div ...

Use a page pattern

To create a page in an application or website based on a page design pattern, create a view (e.g. views/error.pug) with the following:

extends ../node_modules/@antarctica/bas-style-kit-pug-templates/views/bas-style-kit/[page-pattern].pug

block append variables
  - attributes.site_title = 'Example service';
  - attributes.site_description = 'Service to act as an example';
  - bsk_attributes.site_nav_brand_text = 'Example service';
  - bsk_attributes.site_development_phase = 'experimental';
  - bsk_attributes.site_footer_policies_cookies_href = '/legal/cookies';
  - bsk_attributes.site_footer_policies_copyright_href = '/legal/copyright';
  - bsk_attributes.site_footer_policies_privacy_href = '/legal/privacy';

Where [page-pattern] in the extends value is the name of a page pattern, for example:

extends ../node_modules/@antarctica/bas-style-kit-pug-templates/views/bas-style-kit/bsk--page-not-found.pug

block append variables
  - attributes.site_title = 'Example service';
  - attributes.site_description = 'Service to act as an example';
  - bsk_attributes.site_nav_brand_text = 'Example service';
  - bsk_attributes.site_development_phase = 'experimental';
  - bsk_attributes.site_footer_policies_cookies_href = '/legal/cookies';
  - bsk_attributes.site_footer_policies_copyright_href = '/legal/copyright';
  - bsk_attributes.site_footer_policies_privacy_href = '/legal/privacy';

Use a component pattern

To include a component pattern in a view or layout include the relevant mixin and call it with any required parameters. For example:

extends ../node_modules/@antarctica/bas-style-kit-pug-templates/layouts/bas-style-kit/bsk--standard.pug

block append variables
  - attributes.site_title = 'Example service';
  - attributes.site_description = 'Service to act as an example';
  - bsk_attributes.site_nav_brand_text = 'Example service';
  - bsk_attributes.site_development_phase = 'experimental';
  - bsk_attributes.site_footer_policies_cookies_href = '/legal/cookies';
  - bsk_attributes.site_footer_policies_copyright_href = '/legal/copyright';
  - bsk_attributes.site_footer_policies_privacy_href = '/legal/privacy';

include ../../../../mixins/bas-style-kit/bsk--pattern--item-type-header.pug

block main_content
    +pattern_item_type_header('Item type', 'Item title')
    | test content

Patterns

Patterns are used to define preferred ways to pass information to users, and ask information from users, in a consistent way. See the Style Kit documentation for more information.

There are two types of pattern used in the Style Kit and these templates:

  • pages - standalone pages designed to be used with or without customisation using Views
  • components - inline elements designed to be used without customisation using Mixins

Page patterns

These templates include views for all page patterns. In most cases all variants of a pattern use the same view, but with different options. Variables and blocks are used as relevant for setting page content.

See the Style Kit documentation for general information on using these patterns.

'page not found' pattern

No configuration options.

'service unavailable' pattern

An required pattern_content block is available for:

  • contact information
  • details of alternative services

An optional pattern_attributes.availability variable is available for setting the availability line:

  • a value of closed will show conventional text
  • a value of replaced will show conventional text
  • no value will show conventional text
'problem with this service' pattern

An required pattern_content block is available for:

  • contact information
  • details of alternative services
'start' pattern

A required pattern_content_uses block is available for

  • the list of needs the service caters for, shown in the 'Use this service to:' section
    • pass an unordered list of uses [1]

A required pattern_attributes.call_to_action_href variable is available for setting the link of the 'Start Now' call to action button [2].

If the call to action should be a 'Sign in to Start' button, the pattern_attributes.call_to_action_variant variable can be set to sign-in-microsoft [3].

An optional pattern_content block is available for [4]:

  • the 'before you start' section (using a .bsk-before-you-start element)
  • the 'more information' section (using a .bsk-more-information element), including contact information

[1]

block pattern_content_type
  ul
    li use
    li another use

[2]

block append variables
  - pattern_attributes.call_to_action_href = '#'

[3]

block append variables
  - pattern_attributes.call_to_action_variant = 'sign-in-microsoft'

[4]

block pattern_content
  section.bsk-before-you-start
    h2.bsk-h3 Before you start
    p You need some information to use this service.

  section.bsk-more-information
    h2.bsk-h3 More information
    p Some additional information
    p You can also #[a(href='#') contact the Sample Team] for additional support.
'sign in' pattern

A pattern_attributes.call_to_action_href variable is available for setting the link of the 'Start Now' call to action button [1].

An required pattern_content block is available for any additional information, including contact information [2].

[1]

block append variables
  - pattern_attributes.call_to_action_href = '#'

[2]

block pattern_content
  section.bsk-more-information
    h2.bsk-h3 More information
    p Contact the #[a(href='#') Sample Team] for more information.
    p Contact the #[a(href='#') IT Service Desk] if you are unable to sign in.

Component patterns

These templates include mixins for all component patterns. Mixin parameters are used for customising each instance of the component.

Note: Mixin parameters are positional, meaning you need to ensure values are provided in the right order to work.

See the Style Kit documentation for general information on using these patterns.

Item type header pattern

Parameters:

  1. item_type the type or kind of thing the item is, e.g. if the item is a person, it's type is 'person'
  2. item_title a label specific to the item, e.g. if the item is a person their name
+pattern_item_type_header('item_type', 'item_title')

For example:

+pattern_item_type_header('Person', 'Connie Watson')
ORCID iD pattern

Parameters:

  1. orcid_id the ORCID iD of an individual as a URL
+pattern_orcid_id('ocird_id')

For example:

+pattern_orcid_id('https://sandbox.orcid.org/0000-0001-8373-6934')

Using custom CSS/JS

Support is provided for loading additional CSS an/or JavaScript resources, such as application or website specific styling or interactivity, either as references to files, or as inline content.

This support is available in all layouts which inherit from the html.pug layout.

For file resources, variables are provided for adding URLs and optional SRI values. Files will be included in the relevant block automatically, after the Style Kit's own resources if a Style Kit layout is used. Inline content can be added manually to these same blocks for loading after files.

  • CSS resources are outputted in the styles block, at the end of the <head> element
  • JS resources are outputted in the scripts block, at the end of the <body> element

For files:

  • CSS files are added as a resource object to the attributes.site_styles variable
  • JS files are added as a resource object to the attributes.site_scripts variable

For inline content:

  • CSS content should be appended to the styles block
  • JS content should be appended to the scripts block

For example:

extends node_modules/@antarctica/bas-style-kit-pug-templates/layouts/html.pug

block append variables
  - attributes.site_scripts.push({href: 'https://cdn.web.bas.ac.uk/libs/jquery/3.3.1/jquery-3.3.1.min.js', integrity: 'sha256-FgpCb/KJQlLNfOu91ta32o/NMZxltwRo8QtmkMRdAu8='})

//- ... Other content ...

block append scripts
  //- Files in site_scripts will be referenced before this content
  script.
    console.log('jQuery version: ' + jQuery.fn.jquery);

Resource objects

Resource objects have the following properties:

Property Data Type Required Allowed Values Example Value
href String Yes Any URL /css/app.css / https://example.com/js/app.js
integrity String No Any SRI value sha256-ClILH8AIH4CkAybtlKhzqqQUYR4eSDiNTK5LIWfF4qQ=

For example:

{
  href: '/css/app.css',
  integrity: 'sha256-ClILH8AIH4CkAybtlKhzqqQUYR4eSDiNTK5LIWfF4qQ='
}

The integrity property is used to specify a Subresource Integrity (SRI) value for a resource. If specified an integrity attribute and will be added to the generated markup. A crossorigin attribute will also be added for Cross-Origin Resource Sharing (CORS) support with a hard-coded, anonymous, value.

For example, to specify a custom CSS resource, /css/app.css, using a relative URL and a SRI value:

extends node_modules/@antarctica/bas-style-kit-pug-templates/layouts/html.pug

block append variables
  - attributes.site_styles.push({href: '/css/app.css', integrity: 'abc123'});

If needed, you can bypass this mechanism by adding references directly to the styles or scripts blocks using the block append syntax. This might be needed for inline scripts and styles for example.

Note: Make sure to use block append and not block, as the latter will disable this mechanism and won't include the Style Kit's own resources.

Navigation menu items

When using the bsk--standard layout, a navbar is included as part of the 'standard header', which consists of a cookie banner, navbar and site development phase banner.

This navbar consists of three menus (and other elements, documented elsewhere):

  1. a primary navigation menu - aligned left, after brand elements
  2. a secondary navigation menu - aligned right, before the launcher menu
  3. a navigation launcher menu - aligned right, after the secondary navigation menu

The navigation launcher is a restricted menu, used to link to other BAS websites and applications. By default it contains links to the BAS public website and the BAS data catalogue. Other websites and applications can be added as well where relevant.

The primary and secondary navigation menu's support:

The navigation launcher menu, which is implemented as a drop-down menu, supports:

  • navbar drop-down menu items

  • primary navigation menu items should be added to the bsk_attributes.site_nav_primary variable

  • secondary navigation menu items should be added to the bsk_attributes.site_nav_secondary variable

  • navigation launcher menu items should be added to the bsk_attributes.site_nav_launcher variable

Menu item objects have the following properties:

Property Data Type Required Allowed Values Example Value Notes
title String Yes Any string About N/A
href String Yes Any URL /about Ignored if items property is used
items Array No Array of menu item objects N/A Ignored for navigation launcher items

Note: The items property is only recursed once, deeper objects will be ignored.

For example:

{
  title: 'About',
  href: '/about'
}

{
  title: 'About',
  items: [
    {
      title: 'History',
      href: '/about/history'
    },
    {
      title: 'Roadmap',
      href: '/about/roadmap'
    }
  ]
}

- bsk_attributes.site_nav_primary.push({title: 'About', href: '/about'});

Note: These templates do not support highlighting active navigation items. You will need to add the .bsk-active class to the currently active menu item, and if relevant, sub-item, manually.

Navigation menu branding

Navbars are also used to display the name/identity of a website or application, to remind users where they are. These elements are referred to as 'brand' elements within the Style Kit.

In the 'standard header', navbar brand elements are shown on the far left.

Supported brand elements:

  • brand text - set using the bsk_attributes.site_nav_brand_text variable
  • brand image - set using the bsk_attributes.site_nav_brand_img_href variable

Brand elements can be used together or individually, with fix classes applied automatically as needed.

Brand elements are linked to a location specified by the bsk_attributes.site_nav_brand_href variable, which should be the index of each website or application (i.e. /).

Site development phase

The site development phase reflects the stage of development for a website or application, e.g. alpha or live. They are described in the Style Kit here.

For websites or applications that are not firmly in the 'live' phase, a banner should be shown to inform users and request feedback. This forms part of the 'standard header' of cookie banner, navbar and site development phase banner.

In these templates, the bsk_attributes.site_development_phase variable is used to specify the current phase for a website or application. When using the bsk--standard layout, a banner will be shown automatically based on this variable.

To disable this banner, set the bsk_attributes.site_development_phase variable to live-stable. This isn't a real phase but separates a newly released website or application from something more mature.

Experimental development phase

Alternatively, the bsk_attributes.site_development_phase variable can be set to experimental to indicate where an website or application is used for staging or other development/testing activities.

Custom development phase

Less commonly, the bsk_attributes.site_development_phase variable can be set to custom to display non-standard information. This is actively discouraged, except for the following cases:

  • identifying design patterns

To use a custom phase, these variables will need to be set:

  • bsk_attributes.site_development_phase to custom
  • bsk_attributes.site_development_phase_custom.label_classes to an array of classes for the label
  • bsk_attributes.site_development_phase_custom.label_text to the text shown in a label
  • bsk_attributes.site_development_phase_custom.message_text to the text shown alongside the label

For example:

extends node_modules/@antarctica/bas-style-kit-pug-templates/layouts/bsk--standard.pug

block append variables
  - bsk_attributes.site_development_phase = 'custom';
  - bsk_attributes.site_development_phase_custom.label_classes.push('bsk-label')
  - bsk_attributes.site_development_phase_custom.label_classes.push('bsk-label-info')
  - bsk_attributes.site_development_phase_custom.label_text = 'Pattern';
  - bsk_attributes.site_development_phase_custom.message_text = 'This is an example of a design pattern, which are best practice design solutions for specific user-focused tasks and page types.';

Site analytics

To include the Google Analytics universal tracking library (gtag), set the attributes.site_analytics.id property to relevant Google Analytics property ID.

Note: When used the anonymise IP option in Google Analytics is enabled by default.

For example:

extends node_modules/@antarctica/bas-style-kit-pug-templates/layouts/html.pug

block append variables
  - attributes.site_analytics.id = '1234';

Components

Components in these templates are grouped by their kind (e.g. layouts/foo.pug). They are also namespaced in a bas-style-kit directory (e.g. layouts/bas-style-kit/foo.pug).

Components that are specific to the Style Kit are prefixed with bsk--.

Views

Views are used for implementing page patterns. They are essentially layouts but with predefined page content relevant to each pattern.

Layouts

Layouts are 'base' templates from which views or other layouts inherit. Layouts in these templates are hierarchical, with each layout extending the last in this order:

  • blank.pug: lowest level layout, intentionally as minimal as possible and not intended for direct use, unless non-HTML output is needed
  • html.pug: defines a minimal, accessible, HTML5 structure with some recommended best practices for cross-platform compatibility
  • bsk--base.pug: intentionally implements the BAS Style Kit as minimally as possible and not intended for direct use, unless the bsk_standard.j2 layout is unsuitable
  • bsk--standard.pug: defines an opinionated, conventional, page layout with a 'standard' header/footer, recommended as a base for application/website layouts

Layouts can be used using the extend keyword and defining content in the relevant block:

Layout Content Block
blank.pug content
html.pug main_content
bsk_base.html main_content
bsk_standard.html main_content 
extends node_modules/@antarctica/bas-style-kit-pug-templates/layouts/html.pug

block main_content
  p Layout content

Blocks

Blocks are used for template inheritance and provide a logical structure/hierarchy.

Blocks are defined in Layouts, typically with default content using Includes. Some blocks are empty, designed for user content or extensibility.

To implement or override a block, redefine it in a template or view:

block example_block
  p content ...

To append to a block, without overriding its existing content, use append block:

append block example_block
  p appended content ...

Includes

Includes are used for organising content, to make management easier, and to allow common elements to be used in multiple places, typically in Blocks.

For example the content needed for using Google Analytics is encapsulated in the body--analytics-script.pug include.

Mixins

Mixins are used to provide configurable, reusable, functionality.

They are used within other components, such as the navigation menus mixin for processing primary and secondary navigation menus the same way, and to implement component patterns.

Variables

Various elements in these templates are configurable, such as the name of the application or website, or the CSS/JS resources to include. A JavaScript object is used to configure these elements and should be passed to the Pug environment.

Note: In Pug, variables are simply JavaScript variables so all methods and concepts that can be applied to a regular JS variable can be used with these variables too (such as array shifting for example).

These variables should be changed or set for each website or application:

  • attributes.site_title
  • attributes.site_description
  • attributes.site_analytics.id
  • bsk_attributes.site_nav_brand_text
  • bsk_attributes.site_nav_primary
  • bsk_attributes.site_development_phase
  • bsk_attributes.site_feedback_href
  • bsk_attributes.site_footer_policies_cookies_href
  • bsk_attributes.site_footer_policies_copyright_href
  • bsk_attributes.site_footer_policies_privacy_href

These variables may, but don't need to be, changed or set for each website or application:

  • attributes.main_content_classes
  • attributes.site_styles
  • attributes.site_scripts
  • bsk_attributes.site_favicon
  • bsk_attributes.site_nav_secondary
  • bsk_attributes.site_nav_brand_img_href
  • bsk_attributes.site_nav_brand_href
  • bsk_attributes.site_nav_launcher

These variables do not normally, and should not, need to be changed or set:

  • attributes.site_back_to_top_target_id
  • attributes.site_main_content_target_id
  • bsk_attributes.container_class
  • bsk_attributes.site_nav_launcher_title
  • bsk_attributes.site_development_phase_custom.label_classes
  • bsk_attributes.site_development_phase_custom.label_text
  • bsk_attributes.site_development_phase_custom.message_text
  • bsk_attributes.site_footer_ogl_symbol_a_href
  • bsk_attributes.site_footer_ogl_text_href
  • bsk_attributes.site_footer_ogl_text_version

These variables must not be changed and should be treated as read only:

  • bsk_variables.templates_version
  • bsk_variables.bsk_version

Variable reference

Variable Value Type Allowed Values Default Value Notes
bsk_variables.templates_version String Any SemVer value As implemented -
bsk_variables.bsk_version String Any BAS Style Kit version As implemented -
attributes.site_title String Any string 'site title' Typically 1-3 words
attributes.site_description String Any string 'site description' Typically 1-2 sentences
attributes.site_back_to_top_target_id String CSS ID selector 'site-top' Set without the ID indicator (#)
attributes.site_main_content_target_id String CSS ID selector 'site-main-content' Set without the ID indicator (#)
attributes.main_content_classes Array List of CSS classes Empty array See the main_content_container block
attributes.site_styles Array Site style object Empty array See Using custom CSS/JS
attributes.site_scripts Array Site script object Empty array See Using custom CSS/JS
attributes.site_analytics Object Site analytics object Empty object See Site analytics
attributes.site_analytics.id String Google Analytics property ID Not set See Site analytics
bsk_attributes.site_favicon String default 'default' The favicon to use, use 'default' the standard BAS favicon
bsk_attributes.container_class String bsk-container / bsk-container-fluid 'bsk-container' -
bsk_attributes.site_nav_primary Array Site navigation object Empty array See Navigation menu items
bsk_attributes.site_nav_secondary Array Site navigation object Empty array See Navigation menu items
bsk_attributes.site_nav_launcher Array Site navigation object (with restrictions) Empty array See Navigation menu items
bsk_attributes.site_nav_launcher_title String Any string 'Part of British Antarctic Survey' Title of the navigation launcher drop-down menu
bsk_attributes.site_nav_brand_text String Any string 'site name' -
bsk_attributes.site_nav_brand_img_href String URL to image Empty string See Navigation menu branding
bsk_attributes.site_nav_brand_href String URL to content '/' See Navigation menu branding
bsk_attributes.site_development_phase String discovery / alpha / beta / live / live-stable / retired / experimental / custom 'alpha' See Site development phase
bsk_attributes.site_development_phase_custom.label_classes Array List of CSS classes Empty array See Custom development phase
bsk_attributes.site_development_phase_custom.label_text String Any string Empty string See Custom development phase
bsk_attributes.site_development_phase_custom.message_text String Any string Empty string See Custom development phase
bsk_attributes.site_feedback_href String URL to feedback page or other content (e.g. model overlay) '#' -
bsk_attributes.site_footer_ogl_symbol_a_href String URL to OGL information page As implemented -
bsk_attributes.site_footer_ogl_text_href String URL to OGL information page As implemented -
bsk_attributes.site_footer_ogl_text_version String Any OGL version As implemented -
bsk_attributes.site_footer_policies_cookies_href String URL to cookies legal policy # -
bsk_attributes.site_footer_policies_copyright_href String URL to copyright legal policy # -
bsk_attributes.site_footer_policies_privacy_href String URL to privacy legal policy # -

Where a value is listed as 'As implemented' the value set within these templates isn't repeated in this documentation. I.e. the value of thebsk_variables.templates_version variable doesn't change how it's used or what it represents.

Note: The reference above omits variables used to implement empty objects or arrays, such as attributes itself.

Development

Source code for this project is available from two repositories:

To create a local development environment using the GitLab repository [1]:

$ git clone https://gitlab.data.bas.ac.uk/web-apps/bsk/bas-style-kit-pug-templates.git
$ cd bas-style-kit-pug-templates/
$ docker-compose pull
$ docker-compose up

To create a local development environment using the GitHub repository:

$ git clone https://github.com/antarctica/bas-style-kit-pug-templates.git
$ cd bas-style-kit-pug-templates/
$ docker-compose build
$ docker-compose up

This will create a local website designed for testing the layouts, views and some other features of these templates using the Gulp task manager. The pug templates are used

Visit localhost:9000 to access the local website.

Updating dependencies

If package.json is changed the project image will need to be rebuilt and pushed to the private BAS Docker Repository [1].

$ cd bas-style-kit-pug-templates/
$ docker-compose build app
$ docker-compose push app

Periodically, dependencies should be updated to their latest versions and conflicts resolved.

The project Docker image should use the latest Node LTS release (as we don't rely on cutting edge Node features), JavaScript dependencies should be updated to their latest versions [2].

Dependencies listed in package.json can be checked using tools such as Daivd-DM to identify outdated versions.

[1] The first time you use this registry, you will need to authenticate using: docker login docker-registry.data.bas.ac.uk

[2] To update dependencies:

# add or update package to 'package.json'
$ rm yarn.lock
$ docker-compose build app
$ docker-compose run --entrypoint="" app ash
$ mv yarn.lock ./layouts/
$ exit
$ docker-compose down
$ mv layouts/yarn.lock ./

Note: Commit the Yarn lock file, yarn.lock, to the repository.

Dependency vulnerability scanning

To ensure the security of this project, and users of the Style Kit, all dependencies are checked against Snyk for vulnerabilities.

Through Continuous Integration, on each commit current dependencies are tested and a snapshot uploaded to Snyk. This snapshot is then monitored for vulnerabilities.

Testing

Continuous Integration

The BAS GitLab instance is used for Continuous Integration using settings defined in .gitlab-ci.yml.

GitHub mirror

A read-only mirror of this project's repository is maintained on GitHub to allow use by those outside of BAS.

Merge requests WILL NOT be accepted on this mirror.

Release procedures

Before release

  1. create a release branch
  2. build and push the app docker image
  3. close release in changelog
  4. commit changes, merge with master and tag with new version
  5. push the merged release to NPM [2]

Note: If the BAS Style Kit version changes, make sure to bump that version in layouts/bas-style-kit/blank.pug too.

Publishing NPM package

Note: This project includes a .npmignore file to exclude additional files from NPM packages.

To preview the contents of the NPM package:

$ docker-compose run --entrypoint='' app ash
$ npm pack --dry-run

To publish the package to NPM:

$ docker-compose run --entrypoint='' app ash
$ npm login
$ npm publish

After release

  1. bump the version in:
  • package.json
  • layouts/bas-style-kit/blank.pug:
    • bsk_variables.templates_version
  1. push the app docker image [1]
  2. commit changes, merge with master and close post-release branch

Issue tracking

This project uses issue tracking to manage development of new features/improvements and reporting bugs.

Feedback

The maintainer of this project is the BAS Web & Applications Team, they can be contacted through the BAS Service Desk.

License

© UK Research and Innovation (UKRI), 2018 - 2021, British Antarctic Survey.

You may use and re-use this software and associated documentation files free of charge in any format or medium, under the terms of the Open Government Licence v3.0.

You may obtain a copy of the Open Government Licence at http://www.nationalarchives.gov.uk/doc/open-government-licence/