Coding Instructions for the National Library of Medicine's Main Website

General Guidelines

Developers should endeavor to follow the guidelines specified on these pages:

NLM Header/Footer code package information - U.S. Web Design System (USWDS). See https://www.nlm.nih.gov/nlmheaderfooter/uswds-2.12.1.zip
NLM Header/Footer code package information - Bootstrap. See https://www.nlm.nih.gov/nlmheaderfooter/bootstrap.zip

Item: <!DOCTYPE>
- Required?: Yes
- Location?: Very first thing in your HTML document, before the <html lang="en"> tag
- Why needed?: Ensures all pages use the HTML5 Document Type.
- Code: <!DOCTYPE>
Item: <html lang="en">
- Required?: Yes
- Location?: Immediately after the tag
- Why needed?: Accessibility - More information at Item 10A on the Web Sites, Web Applications & Software checklist [Excel] which is linked from the HHS Accessibility Compliance Checklists page.
- Code: <html lang="en">

Item: meta-name viewport tag
- Required?: Yes
- Location?: Before the ending </head> tag
- Why needed?: Ensures that the browser will scale to the specified viewport
- Code: <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">

Item: meta-http-equiv tags
- Required?: Yes
- Location?: After opening <html> tag
- Why needed?: Ensures Proper Encoding
- Code:
  - <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    - Displays the webpage in EdgeHTML mode, which is the highest standards mode supported by Internet Explorer, from Internet Explorer 6 through IE11.
  - <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    - Specifies the character encoding for the document.
  - <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"/>
    - Displays the webpage in EdgeHTML mode, which is the highest standards mode supported by Internet Explorer, from Internet Explorer 6 through IE11 and Chrome Frame.

Item: Contact email address tag
- Required?: No, but strongly recommended
- Location?: Before the ending </head> tag
- Why needed?: Allows the NLM broken link checker to send a broken link report to the email address.
- Code: <meta name="NLM.Contact.Email" content="EMAIL_ADDRESS@something_something.nih.gov" />

Item: Google Tag Manager
- Required?: No, but encouraged
- Location: First entry in the <body> tag
- Why needed: Used to gather more reliable page usage statistics
- Code: Contact NLM for information about this code.

Item:
Required?: Yes
Location: Immediately after the Google Tag Manager Code
Why Needed?: Gives users ability to tab directly to page content .
Code: <a class="sr-only sr-only-focusable" href="#skip" title="Skip the navigation on this page">Skip Navigation Bar</a>

Use the information linked from README - Sample code for developers whose non-templated pages live on the NLM main website and want their pages to resemble the NLM main templated pages as a foundation for your pages.
The README page refers to a file which:
- Contains in the items listed in the Mininum Specifications section above.
- Will give your page the header and footer code needed to be consistent with NLM main templated pages.
- Will update your page with the emergency banner when banner is turned on for all NLM Main templated pages.

NLM staff make an effort to keep the The README page and the files it references consistent with current NLM Main template specifications.

Last Reviewed: March 15, 2023