[Ger-Poland-Volhynia] Double letters

[Eduardo Kommers]

Dear friends,

 

The name KOMMERS was written sometimes with one "M" with a dash over the
letter, meaning a double "M". I see this happening with the letter N as
well.

Some years ago I made this question here but I think I lost these messages.

Is anyone here aware of this grammatical situation involving German-Russian
family names? Where did it come from?

Thanks,

Eduardo Kommers