Guildmasters are able to send out invitations to prospective members. These come in the form of letters from the guild which the aspirant member then presents to a guild-tutor to receive initiation as a guild apprentice.
Type PERMIT followed by the youngster's fullname, followed by the number of days the invitation permit is to last, e..g. PERMIT YOSSARIAN 7. This sends off the letter. You can type PERMITS to review a list of outstanding permits circulating the land in the name of your guild.
Those individuals holding letter-invites can only accept invitations before the designated guild tutors (by typing ACCEPT INVITATION). It may be they need to knock on the guild door to bring forth the appropriate tutor, or seek the tutor somewhere in the guildhouse. Invitations overcome recruitment restrictions and thus allow a Guildmaster to initiate an eager new member without having to meet them face to face.