Characters that may be used in keys

[Kirk_Masden]

Hi! I have a fairly simple question that I couldn't find the answer to in the documentation on keys:

https://support.google.com/appsheet/answer/10106672?hl=en

The question is: Are there any restrictions on the characters that can be used in a key?

On my spreadsheet I thought I'd append a couple of characters to a preexisting key to make a new key the record is when it is copied to another table. It occurred to me that I could reduce the number of digits I need to append to the key if I made the Google spreadsheet choose between a range of ascii characters, such as the following:

--- reposting without the character string, which may have prevented previous versions of this inquiry from appearing properly ---

I wonder, though, if any of these characters might cause some sort of issue. I considered testing it myself but I thought I'd ask first. Does anyone know?

P.S.  This is my third attempt to post this inquiry.  Two previous attempts may not have appeared because of the vary characters I wanted to ask about.

[Kirk_Masden]

Here's the list of characters that may have prevented previous versions of the post from appearing:

0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}

[Steve]

To my knowledge, there are no restrictions on the characters that may be used in keys. I can't imagine why there would be. 🤔

[Steve]

https://www.googlecloudcommunity.com/gc/AppSheet-Q-A/Characters-that-may-be-used-in-a-key/m-p/452827...

[Kirk_Masden]

I'm not sure what happened.  For some reason my post didn't appear so I posted again.