I see the point. The correct translation is [Strg] because all German keyboards layout have a [Strg] instead of [Ctrl] key since the last 30 years I use keyboards.
Wikipedia: German keyboard layout
and Wikipedia: Keyboard layout
I just recognize that unfortunately an international keyboard layout seems to be not supported in Sigil. That's the problem with language and translations. Surprises came up where you do not expect it.
Your point is correct and I think I need to change this back to Ctrl as long as there is no difference of international keyboard layouts in Sigil. By the way you are the first one who have recognize (ore let me say use) this. I had made the change some when mid October.
Thanks for your comment.
@User_none and meme
I will change this back but it is a problem for translation and documentation. People who a working with IT will have no problem to understand that [Ctrl] is the same as [Strg] but there is still the point that this key do not exist in a keyboard layout for Germany and Austria. As this isn't a common standard for these countries. My guess is to describe this in the documentation and may be in the shortcut editor window. Then there is no misunderstanding.
When I look into other programs like MS Windows, MS Office, Adobe products etc. this key will be translated and used as [Strg]. This is common standard. Maybe this is something you can implement some when in the future.
Have a nice sunday.