[whpalmer4]

If you use the iOS apps, your approach is better that Kourosh's approach, because the iOS apps do not include the contents of the notes fields in searches!

When I've done this in the past, I used something like Tag: instead of just # to indicate that the string following was a tag. Less chance of an accidental match, and it also allows for a search which turns up all actions with tags (I have many actions which contain a # somewhere, so just searching for that wouldn't be useful).