A hairnet is read as rules, routine and keeping things contained. Dream books link it to work that asks for order, and to holding stray thoughts in place.
Has this come up in your dreams before? What was going on in your life then?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.