Ability to choose subtopics

It would be great to be able to choose which subtopics to include (or exclude) from astroph when generating personal streams. For example only articles from [astro-ph.EP] and [astro-ph.SR] or all except [astro-ph.IM].

Or one step further would be to include articles that contain specific keywords. E.g. include articles which include Radial Velocity, astroseismology or Black Holes.
This could be then personally tuned to suit the research interests of the listener.

This is really neat project and have enjoyed listening so far.
Jason

No file, test, or entry point is named in the issue. Start by locating the code that generates personal streams from astroph sources, then determine how subtopic inclusion and exclusion are represented; done means users can select astroph subtopics and optionally filter articles by keywords.

Written by the indexing model from the issue text.