- The [snvalid()](https://help.autodesk.com/view/ACD/2016/ENU/?guid=GUID-2EFBE198-9860-456B-A090-206C743ACB90) [[AutoLISP]] function checks the symbol table name for valid characters.
	- Symbol tables names are layer- linetype-, style names ...
	- Characters disallowed in symbol table names:
		- `< >` less-than and greater-than symbol
		- `/\` forward slash and backslash
		- `"`	quotation mark
		- `:` colon
		- `?` question mark
		- `*` asterisk
		- `|`vertical bar
		- `,` comma
		- `=` equal sign
		- `` ` `` backquote
		- `;` semicolon (ASCII 59)
	- Known exceptions, used by [[AutoCAD]] for internal usage:
		- `*ADSK_...`
		- `*ACMAP`
		- `*TEMPORARY`
		- The `*` as first and **only** as first letter seems to be accepted by [[AutoCAD]]
			- `*XYZ` is OK
			- `XYZ*` is not OK