There are 32 hidden gems in MacOS which are not widely known, and one (.nobackup) I recently discovered by myself. These allow more granular control over indexing, iCloud synching and Time Machine inclusion. I am not going to discuss here wether the syntax is clumsy, rather I am very glad that at least these exist. So here goes:

.nosync

Any file or directory where the name contains “.nosync” is ignored by iCould synchronisation

.noindex

Any file or directory where the name contains “.nosync” is ignored by Spotlight

.nobackup

Any file or directory where the name contains “.nobackup” is ignored by Time Machine
2019-04-05 Hmm, doesn’t seem to work any more… I’m sure it did once when I tested.