Another reason the GREP solution is not great: Yes, I can get it to work for my "Part Number" paragraph style (once I get the new character style and revised paragraph style into every single document). But spell check still stops on random things in the table that uses our basic "Table body" style. Don't want "no language" on that style.
You can use find/change to assign no language to part numbers as you open the older files to work on them. What do your part numbers look like?
Thanks for your response, Peter. We unfortunately have several different possibilities for part number format...(1234A12; 12345B12; etc.). I could make some find/change queries for them (I already have some scripts that need to recognize part numbers, so I've dealt with that before). However, it goes beyond part number I'm realizing. We may have "...the 12-ft. cord..." in copy. Or "303SS..." in a table subhead. And many, many other letter/number combinations.
The more I read, other than getting a third-party plugin, I think my only option is to add the GREP style to every single one of our paragraph styles and have the users update their styles every time they open a document.