Prefetch glossary + prerendering

[hamishwillee]

FF115 adds support for spec compliant prefetch, following a round of standardization. Essentially this is a Sec-Purpose: prefetch header, requirement that the Accept header matches the normal navigation request, and Sec-Fetch-Dest must be empty.

No one else complies yet, and the others are a bit of a hodge-podge in terms of the HTTP backend. What I have already done is added the Sec-Purpose: prefetch header doc and that is where compatibility will be tracked as we head towards it.

This PR updates the glossary for Prefetch (and the prerrendering too). What it aims to do is make this new specification behaviour clear. I have also made it clear in a note that this is new behaviour and hinted at the old behaviour. But I have deliberately not tried to describe that behaviour in detail - Chrome does some "interesting" stuff with the HTTP cache and ignores the requirement for the Sec-Fetch-Dest to be empty.

It also deletes the old link handling FAQ, which was mostly "old behaviour".

Related docs work in #27171

[github-actions]

Preview URLs (6 pages)

• /en-US/docs/Glossary/Prefetch
• /en-US/docs/Glossary/Prerender
• /en-US/docs/Mozilla/Firefox/Releases/44
• /en-US/docs/Web/HTML/Attributes/rel/preload
• /en-US/docs/Web/HTML/Attributes/rel
• /en-US/docs/Web/Performance

Flaws (30)

Note! 3 documents with no flaws that don't need to be listed. 🎉

URL: /en-US/docs/Mozilla/Firefox/Releases/44
Title: Firefox 44 for developers
Flaw count: 17

• macros:
  • /en-US/docs/Web/CSS/@page/marks does not exist
  • /en-US/docs/Web/CSS/size does not exist
  • /en-US/docs/Web/API/MessageEvent/initMessageEvent does not exist
  • /en-US/docs/Web/API/Window/onorientationchange does not exist
  • /en-US/docs/Web/API/Element/webkitMatchesSelector does not exist
  • and 6 more flaws omitted
• broken_links:
  • Can't resolve /en-US/docs/Web/JavaScript/Typed_arrays
  • Can't resolve /en-US/docs/Mozilla/Add-ons/Firefox_for_Android/API/Snackbars.jsm
  • Can't resolve /en-US/docs/Mozilla/Firefox_for_Android
  • Can't resolve /en-US/docs/Mozilla/Add-ons/SDK/Tools/cfx
  • Can't resolve /en-US/docs/Mozilla/Add-ons/SDK/Tools/jpm
  • and 1 more flaws omitted

---

URL: /en-US/docs/Web/Performance
Title: Web performance
Flaw count: 11

• broken_links:
  • Can't resolve /en-US/docs/Learn/Performance/Mobile
  • Can't resolve /en-US/docs/Web/API/Performance_API/Using_the_Performance_API
  • Can't resolve /en-US/docs/Web/API/Resource_Timing_API/Using_the_Resource_Timing_API
  • Can't resolve /en-US/docs/Web/API/Resource_Timing_API
  • Can't resolve /en-US/docs/Web/API/Performance_Timeline/Using_Performance_Timeline
  • and 6 more flaws omitted

---

URL: /en-US/docs/Web/HTML/Attributes/rel/preload
Title: rel=preload
Flaw count: 2

• broken_links:
  • Can't resolve /en-US/docs/Web/CSS/Media_Queries/Using_media_queries
  • Can't resolve /en-US/docs/Web/CSS/Media_Queries/Testing_media_queries

External URLs (3)

URL: /en-US/docs/Glossary/Prefetch
Title: Prefetch

• https://developer.chrome.com/blog/prerender-pages/ (1 time) (Note! This may be a new URL 👀)

---

URL: /en-US/docs/Glossary/Prerender
Title: Prerender

• https://developer.chrome.com/blog/prerender-pages/ (1 time) (Note! This may be a new URL 👀)

---

URL: /en-US/docs/Mozilla/Firefox/Releases/44
Title: Firefox 44 for developers

• https://bugzil.la/1214819 (1 time) (Note! This may be a new URL 👀)

(comment last updated: 2023-06-30 15:00:11)

[hamishwillee]

@noamr Would it be possible for you to review this PR, in particular /en-US/docs/Glossary/Prefetch and also the linked HTTP header doc Sec-Purpose (though that might not be published live yet). This essentially is my take for your requirement on #23553.

I'm interested in whether this is sufficient, and of course correct.

[hamishwillee]

Thanks @noamr - really appreciate your advice. I think I've addressed it (mostly be deleting the bits that were confusing, and not strictly necessary).

[Rumyra]

OK this all looks great @hamishwillee - I got stuck because I'm uncomfortable with closing link elements /> which I know there was a huge discussion about markdown lint (and thanks @bsmth for fixing) - but I think this uncovers some intricacies ... something for more editorial discussion

[hamishwillee]

Thanks @Rumyra @bsmth - much appreciated. The closing tags had to go as I understand it. Only there because either bad habits on my part or I copied from somewhere else that was incorrect.