I have searched here and the internet and found no answer. I found it myself. The previous answer did not understand the question and provided wrong answers. The topic was closed, years ago.
My situation. I was trying to figure out ABS and created different styles. I did not want those wrong styles to appear in the list anymore. Here what I did:
Select the cells you wanted to format from the spreadsheet
Format cells / from the menu bar
category
user defined
select the style you created that you want to delete (ie click on it to create highlight)
find “format code” at bottom of view
select the red X
it should delete
you can continue to do these steps for each wrong style you want to delete
I hope this helps,.
