Mike, I used your code but modified slightly because I don’t want to insert an extra space after the formatting characters if it already exists.
So the expression captures a { follwed by a backslash followed by any number of non-space characters followed by a space. Then it captures the closing } and puts them together with a space between them.
Example:
hcitcl>echo $text
DURATION}{fs24 }{fs24 OF}{fs24 }{fs24 SERVICE:}
hcitcl>regsub -all — {({BS*?s)(})} $text {1 2} text
1
hcitcl>echo $text
DURATION}{fs24 }{fs24 OF}{fs24 }{fs24 SERVICE:}
Thanks for the help!!