Good filename for a PDF invoice

Most filenames are USELESS for the customer. I have files like DKX4940207.pdf and similar. When I see such a filename, I ask myself: From "WHOM" did I buy? A good filename is:

Company_name_invoicenumber_2020_07_21.pdf

Good and bad characters in filenames

1. Do NOT use space in filenames. Why ? When put the file on the web, the space in the URL will be converted to %20 AND you can not double click and select the whole filename.


2. Use underscore _ in stead of dash -
   1) It is easier to read a long filename, especially on the web. 2) You can not double click a dash. You can double click an underscore.
   
   Double click the word "invoicenumber":
   Company_name_invoicenumber_2020_07_21.pdf
   Company-name-invoicenumber-2020-07-21.pdf