SQLITE what are the restricted characters for identifiers

I am trying to build a system where SQL parameters gets automatically bound to new queries. According to this thread:

SQL Server - Invalid characters in parameter names

The @, _ and # characters should be allowed inside identifiers. So I tried to build parameters as:

:tablename#fieldname

But when doing do I get error:

PBdatabase.select_query: [1] DB[2] prepare() SELECT * FROM creature WHERE pk = :creature#pk [near "#pk": syntax error]

It seems it does not like the # character, I tried with the underscore, it seem to work but I am already using the underscore in field names. This is why I wanted to use a different character.

Since the thread above talked about SQL server, the restricted characters could be different in SQLITE. I found the list of SQLITE restricted keywords, but not characters.

Does anybody know which other special character I could use?