This are season and episodes numbers as written on the screen. They appear if they are inside the tvguide.xml... If you want to have a closer look this is how they are noted inside the tvguide.xml:can not find where MP2 is getting those numbers next to episode title from.
XML:
<episode-num system="xmltv_ns">3.4.</episode-num>
where the count starts with 0 not with 1 This example above is season 4 episode 5.
Far the most people like to have those information, if available... So there are many tools out there that adds those numbers if they are missing in the "raw" EPG data.. But I'm not aware of any tool to remove them. And I also don't know how to disable them without modifying the skin files...