Ability to rename existing field?

For invoice numbering. Are you use any prefix format?
Example : IN15000

If yes.
You can replace “#” symbol with your own prefix.

Settings > Invoice Template > Invoice Number Prefix.

If you leave it as blank. “#” symbol will appear.

Only ‘Quote’ & ‘Purchase Order’ you can remove “#” symbol by edit your template.

I don’t know if somebody know how to eliminate “#” symbol with different ways.