So that others may also comment, here is some information about what rules we would like to enforce (in ftrack's web interface and in ftrack Connect, using python for example).
We need to make sure projects, shots, assets, tasks, and also publishing versions, follow these rules :
Names must begin with a letter, and they should not contain any of these : spaces, non-english accents, non-unicode characters, special characters, dash -
The above sentence can be explained the other way around : names must begin with a letter, and must only contain standard english letters, numbers, and underscores.
As a side note, we also make sure that folder and file names (which come from entities names) also follow this :
-Folder names are all uppercase.
-File names are all lowercase.
I have worked for several companies that have chosen these same rules (because less strict rules often cause compatibility problems in softwares and scripts), but of course I guess other companies may prefer other rules.