Bug overview description.
The API documentation for the tags/list function mentions a name_pattern attribute, where name_pattern=foo would seem to be equivalent to the name=*foo*. Adding it to API queries does not seem to affect the result.

What part(s) of the site page(s) are affected?
The JSON and XML API function calls.

What is the expected behavior?
name=*_the_* and name_pattern=_the_ should return the same results.

What actual behavior is given instead?
Passing name_pattern=_the_ to the tag/index does not alter the returned tag list when compared to the default return value

Time of incident (if applicable).
N/A

Can you reproduce the bug every time?
Yes

What steps did you take to replicate this bug?
See expected/actual behavior.

Errors or other messages returned (if any).
None.

While some people may see name_pattern as redundant, it'd actually come very handy to implement tag auto-completion since the tag currently being typed could be passed as such instead of having to fence it with jokers before calling the API, which can be tricky with some frameworks/libraries.