Since ham radio call signs can contain both the letter O and the digit 0 at the same time, the zeros are often represented as a slashed zero in print. But because there's no ready-hand (Unicode) character for this, the letter Ø is used most often instead, since one cannot always use a monospace font which already represents the zero in slashed form. (This problem could also occur in other cases, such as printing hashes or codes.)
There's a lot of ham radio logging software outside that supports a workflow for printing QSL cards or label stickers, and I'm not sure if any of these supports the replacement of zeros with Ø before print—only in call signs, and not in other data such as date, time or frequency. The software I use on Ubuntu, CQRLOG, exports QSOs into a CSV file that can be read in by gLabels to perform or prepare the actual print. I wanted a step in between that transforms that CSV file by substituting that Ø only in call signs. It took me some time, but here's my solution (showing a bogus CSV line):
$ echo "30-Oct-2018,12:04,AB0/K100ABC/P,14.104,F0und AA2/YZ300ZY/0" \
> | perl -pe '1 while s|(.*[A-Z0-9][A-Z0-9/]+)+0([A-Z0-9/]*.*)|\1Ø\2|g'
30-Oct-2018,12:04,ABØ/K1ØØABC/P,14.104,F0und AA2/YZ3ØØZY/Ø
I stuffed this regex pattern into this alias:
alias qsl0='src=$HOME/path/to/qsl.csv; \
cp -p $src $src.orig; \
perl -pe \
"1 while s|(.*[A-Z0-9][A-Z0-9/]+)+0([A-Z0-9/]*.*)|\1Ø\2|g" \
< $src.orig > $src'
Update: Fixed the pattern to allow prefixes that start with a digit.
