Naming of Worksheets (display of existing worksheet name)

[nicholassmall]

I can find no rules regarding the naming of worksheets. However, if I have a worksheet named 'A&B' and double-click on that name to edit it, then the Old Name is displayed as 'AB', although'&' displays properly in the New Name field.

[raitis.veksejs]

If you save the file in .pmdx (.pmd) format there don't exist sheet name restrictions. If the file is saved in .xlsx (.xls) format, see the screenshot about restrictions. About symbol "&" I'll ask our developers' team why it is displayed wrongly during renaming.

[el48tel]

Doesn't the ampersand switch the name into hexadecimal mode.
So '&20' corresponds to the ' ' space character.
Using the hexadecimal allows you to use characters which would otherwise be disallowed because they are used by the machine for specific purposes ..... for example '\' defines folders.
Please feel free to correct me.