Add descriptor requirement to @font-face

[ryo-manba]

Description

Added a missing requirement.

Motivation

Clarifies the spec:

@font-face rules require a font-family and src descriptor; if either of these are missing, the @\font-face rule must not be considered when performing the font matching algorithm.
CSS Fonts Module Level 4

Additional details

The wording follows the same style as the description for the @font-face src descriptor.

Related issues and pull requests

[github-actions]

Preview URLs

• /en-US/docs/Web/CSS/@font-face

Flaws (48)

URL: /en-US/docs/Web/CSS/@font-face
Title: @font-face
Flaw count: 48

• macros:
  • Wrong xref macro used (consider changing which macro you use). Error processing path /en-US/docs/Learn/CSS
  • Wrong xref macro used (consider changing which macro you use). Error processing path /en-US/docs/Learn/Getting_started_with_the_web/CSS_basics
  • Wrong xref macro used (consider changing which macro you use). Error processing path /en-US/docs/Learn/CSS/First_steps
  • Wrong xref macro used (consider changing which macro you use). Error processing path /en-US/docs/Learn/CSS/First_steps/What_is_CSS
  • Wrong xref macro used (consider changing which macro you use). Error processing path /en-US/docs/Learn/CSS/First_steps/Getting_started
  • and 43 more flaws omitted

(comment last updated: 2025-01-21 13:27:31)

[chrisdavidmills]

Hello @ryo-manba, and thank you for the improvement to this page!

Your update looks fine, but while I was here I decided to make a couple of grammar improvements to the page too. I hope you don't mind.