On 5 Aug 2016, at 19:49, M. wrote:

I was trying to find out if there's a way to change the title of open tabs

(currently: full file name) […]

This cannot currently be changed. Can you tell me what you would like to change it to?

I have a note on the TODO about introducing disambiguation when multiple tabs have the same name (e.g. index.html), so if this is basically your goal, it might work better as a native feature (since always showing “disambiguation” would take up a lot of space).

Btw: You can give documents a custom display name, but currently only via mate when they are opened, but this display name is used beyond just the tab titles, I assume you want to keep the original display name in other locations.