That's a very vague question. There are times where we can recover a charge and then reuse it after work has been performed. This is acceptable at certain times.
Re-using it in the same system you just pulled it out of as long as its clean and was recovered correctly is ok.
Removing it and reselling it as new refrigerant at a different location is NOT ok for a variety of reasons.
it may be used in any system that the owner has that uses that same refrigerant, even at other locations. it may not be resold to someone else for use in their system/systems though.