How to use regular expression comments

when learning the annotation capabilities of regular expressions, comments always cause matching exceptions. For example,

use 

\d{2}

match 24 can be successful. If you add a comment, it becomes 

\d{2}(?-sharp)

match 24 fails.
after looking up a lot of information, I can"t find an explanation. Please give me some guidance. Thank you very much!

Comment regular-expression
Mar.09,2021

which language do you use, and then ask yourself two questions: are you sure annotations are supported? Are you sure Chinese annotations are supported?

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MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-437a934-1e64.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-437a934-1e64.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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