@truhe @feditips Instances might not have elasticsearch installed (that's the search backend), because it needs lots of resources. So, "prohibited" no, but "not available" is a possibility.

Whether you can search depends on whether the server you're on has the feature installed, and whether the profile you're searching (no matter which server it is on) has opted in.

@truhe @feditips They can choose to not deploy the full text search on their instance* so their users can't search, but users could still opt in to be included in the search index on other instances.

*) ElastiSearch/Opensearch is quite a resource hog, so maybe not every instance admin will be able to set it up