An old surveyor I used to work with in a research lab told me that it was an unwritten rule that you had to put back what you couldn't find.
Surveyors use the acronym GIN for Galvanised Iron Nail - which is a useful intermediate marker between the official survey marks.
When he was working up in Darwin at one point, he had a map stating there was a "GIN in gutter". He said he couldn't find her, and had no idea how to put her back.
