Pacman doesn't have an internal way of delivering a message after installing a package. For a package to do this, it needs to be echo'd with an .install file. Kind of a hack since .install files are supposed to run necessary commands after an install, not be loud and do nothing. Also, this means that every notification looks different, which is kinda sloppy as far as aesthetics go. optdepends have this same problem, too.

It would be nice if there was some sort of formatting for the text in some way. For example, if the message was to be stored in a file, paragraphs of text would not be separated by newlines: it'd be word-wrapped on display. And perhaps instead of having an important three-line message blow by discreetly (this happens all the time), it would simply install without displaying anything and deliver the messages at the end. Something like "There are 5 unread messages from pacman." and the user can read the messages at any time by a command.