Board Thread:Help!/@comment-43874324-20200131175851/@comment-5918438-20200131181731

User subpages are allowed for use as personal sandboxes, so long as they aren't being used to publish fanfic, as outlined at T:USER PAGE. This means you're free to create User:WaltK/Example, and generally speaking (providing no user page policy is broken), it will not be tampered with.

See Tardis:Bad uses for user pages for more on where we draw the line.