This is how we collectively alert each other when there is a bug with a certain software. For instance, you might describe all the details you can of a certain bug you found on Openbook and then tag the post: #openbook #bugreport

See: hashtag combos

BTW did you know that the term "bug" came from when computers were as big as a room and used punch cards to represent the code? It referred to a literal bug messing up the computer, either getting caught up in the computer chips, or getting in the way of an accurate reading of the punch cards.