Communicating = subarachnoid space is continuous with the ventricles (i.e. no blockage, such as aquaductal stenosis or Budd-Chiari).
Normal pressure is a type of communicating hydrocephalus. Increased intraventricular pressure --> increased ventricular size --> due to increased CSF production. However, ICP is not exceedingly high such that associated high-ICP Sxs occur.
As far as I'm aware, pseudotumor cerebri is just increased ICP due to generally idiopathic causes. However, I've seen a couple practice USMLE practice questions already where they like danazol as causing it. I think ~13% got that right on USMLE Rx when I had gone through that QBank. Danazol is also associated with peliosis hepatis.