Original text:
The Use-As-Dictionary response header is a Structured Field STRUCTURED-FIELDS sf-dictionary with values for "match", "match- <del> search", "match-dest", "ttl", "id", and "type". </del>  2.1.1. The "match" value of the Use-As-Dictionary header is a sf-string <del> value that provides the "pathname" of a URLPattern (https://urlpattern.spec.whatwg.org/#dom-urlpatterninit-pathname). </del>  <del> The "match" is a URL path relative to the full request URL of the dictionary.  The request URL for the dictionary itself is used as the "baseURL" for constructing the URLPattern (https://urlpattern.spec.whatwg.org/) that is used for matching the dictionary to relevant requests when running dictionary-url-matching. </del>  <del> The URLPattern used for request matching does not support regular expressions (https://urlpattern.spec.whatwg.org/#token-type-regexp) in the "match". </del>  <del> The "match" value is required and MUST be included in the Use-As- Dictionary sf-dictionary for the dictionary to be considered valid. </del>  <del> 2.1.2. </del>  <del> The "match-search" value of the Use-As-Dictionary header is a sf- string value that provides the "search" of a URLPattern (https://urlpattern.spec.whatwg.org/#dom-urlpatterninit-search). </del>  <del> The "match-search" is the match pattern for the searchpart of the request URL and does not support regular expressions. </del>  <del> The "match-search" value is optional and defaults to the asterisk wildcard token "*". </del>  <del> 2.1.3. </del>  The "match-dest" value of the Use-As-Dictionary header is a sf-string value that provides a request destination

Reviewer comments:
This changes the URLPattern match to use a single match pattern to be consistent with other uses of URLPattern.
NAME NAME this is an attempt at a change to have it use a single string for pattern construction. I don't feel great about the same-origin check part of the validation but I don't see why it wouldn't work. It still allows for people to waste bytes by not using path-relative patterns so I may have to re-open the issue around that but should provide the consistency you were asking for. This would be instead of PR .
a couple nitpicks while passing by

Revised text:
The Use-As-Dictionary response header is a Structured Field STRUCTURED-FIELDS sf-dictionary with values for "match", "match-  <ins> dest", "ttl", "id", and "type". </ins> 2.1.1. The "match" value of the Use-As-Dictionary header is a sf-string  <ins> value that provides the URLPattern to use for request matching (https://urlpattern.spec.whatwg.org/). </ins>  <ins> The URLPattern used for matching does not support using Regular expressions. </ins>  <ins> The following algorithm will return TRUE for a valid match pattern and FALSE for an invalid pattern that MUST NOT be used: </ins>  <ins> Let MATCH be the value of "match" for the given dictionary. </ins>  <ins> Let URL be the URL of the dictionary request. </ins>  <ins> Let PATTERN be a URLPattern constructed by setting input=MATCH, and baseURL=URL (https://urlpattern.spec.whatwg.org/). </ins>  <ins> If PATTERN has regexp groups then return FALSE (https://urlpattern.spec.whatwg.org/#urlpattern-has-regexp- groups). </ins>  <ins> Return True. </ins>  <ins> The "match" value is required and MUST be included in the Use-As- Dictionary sf-dictionary for the dictionary to be considered valid. 2.1.2. </ins> The "match-dest" value of the Use-As-Dictionary header is a sf-string value that provides a request destination