Remove references to since MU

[spacedmonkey]

Searching the code there are 168 references to since MU. This is confusing if you do not know the history of multisite and it's merge into core. These docs should be changed to reflect the core versioning numbers, which is since 3.0.0

[jeremyfelt]

There is something nice about knowing something was built (and has a history of its own) before the merge. I've used that as an indicator in the past that I may need to hunt through ​https://mu.trac.wordpress.org/ for answers. That said, if you blame back to the merge changeset, then you'll probably know you can go further.

Do we lose anything by changing them all to 3.0.0?

[johnbillion]

I believe the reason @since MU was used is just that, it indicates there is history prior to the 3.0 merge.

I'd favour a syntax such as @since MU (3.0.0) if it helps newcomers.

[sathyapulse]

@spacedmonkey @desrosj @johnbillion The format suggested by @johnbillion make sense. I have created a patch file with the changes. There are 168 matches across 17 files.

[spacedmonkey]

How about @since 3.0.0 (MU) ? The key thing is WordPress version is more important at this point.

[DrewAPicture]

Replying to spacedmonkey:

How about @since 3.0.0 (MU) ? The key thing is WordPress version is more important at this point.

I prefer the @since MU (3.0.0) version because it still (correctly) documents that the code was sourced from MU, then uses 3.0.0 to provide context.

[DrewAPicture]

In 41200:

Docs: Reduce confusion in @since MU notationss by indicating the WP version (3.0.0) the code was merged into core while retaining the original context.

Props sathyapulse.
Fixes #41509.

[ocean90]

@DrewAPicture Does this require a change on DevHub (​https://developer.wordpress.org/reference/since/MU/)?

​https://make.wordpress.org/core/handbook/best-practices/inline-documentation-standards/php/#miscellaneous needs also an update.

[DrewAPicture]

Replying to ocean90:

@DrewAPicture Does this require a change on DevHub (​https://developer.wordpress.org/reference/since/MU/)?

​https://make.wordpress.org/core/handbook/best-practices/inline-documentation-standards/php/#miscellaneous needs also an update.

Yeah, working on an exception for the parser so they still map to mu. I'll update the standards today.

[johnbillion]

In 41714:

Docs: Correct some @since MU notation that was broken in [41200].

Every function introduced by MU was introduced in 3.0.0 as this was when MU was merged.

See #41509