Namespaces are one very important use case. Additionally I would be interested in having an option to only block account creations (T17273#10066969). Sometimes you want to prevent an LTA from creating accounts using their typical IP ranges, but instead of blocking any IP editing from that range use an abuse filter to just prevent certain IP edits, if the range is shared with good faith users...

In T373367#10093232, @Johannnes89 wrote:

Namespaces are one very important use case. Additionally I would be interested in having an option to only block account creations (T17273#10066969). Sometimes you want to prevent an LTA from creating accounts using their typical IP ranges, but instead of blocking any IP editing from that range use an abuse filter to just prevent certain IP edits, if the range is shared with good faith users...

Thanks for the thoughts. Could you file a separate task for the account creation partial block?

But only in standard namespaces? What with project-based namespaces?

T45934: harmonize namespaces towards languages and projects proposed to renumber e.g. Portal namespaces of all wikis to same number. However it is a long way to go.

bring feature parity with local blocks,

Is this a part of some larger work/goal? Either way this task does not state why that'd be useful, and it should. Parity on itself should not be a reason. I said this because I'm struggling to understand how globally blocking a user from all – say portal – namespace across all wikis would be useful.

If a user have to be blocked globally, then their problem has reached extreme stages where partial retrictions (including a single site full block on each individual wikis) are no longer useful.

I think a use case given to me would be to block a user from the main space or the project space on every project.

I filed this here so that it wouldn't be forgotten. It's not planned by any WMF team at this time.

In T373367#10121787, @Ammarpad wrote:

If a user have to be blocked globally, then their problem has reached extreme stages where partial retrictions (including a single site full block on each individual wikis) are no longer useful.

You are correct when you think of just a single user, but this feature would be useful for global range blocks – e.g. if an LTA frequently targets pages in the project namespace of different Wikimedia projects, editing via IP from a range which also has good faith edits from other people in the article namespace, a partial global range block would be a great option.