Hooks/Docs: link_category in deprecated.php missing xref to bookmark-template.php

[apermo]

Problem

apply_filters( 'link_category', ... ) in wp-includes/deprecated.php:1063 (inside deprecated get_links_list()) has no PHPDoc or cross-reference comment. The canonical PHPDoc lives in wp-includes/bookmark-template.php:273-279.

Fix

Add /** This filter is documented in wp-includes/bookmark-template.php */ above the call.

Related to https://core.trac.wordpress.org/ticket/64224

[apermo]

also possible irrelevant but correct.