The Guild of Maintainers (also known as the "Maintainers Guild", or simply the "Maintainers"), was one of the most important of the D'ni Guilds. The guild crest is an open book with an unblinking eye above it, and the guild color was burgundy.
The Maintainers owned numerous Ages. One such Age, written exclusively for the Maintainers, was Gahreesen, which appears to have been a mix of both training and prison facilities.
The Maintainers held several different and diverse duties. One of the most important was the overseeing and regulation of the Art. Any Age written had to be first approved by the Maintainers before it could be accessed. Ages that did not meet the Maintainers' standard were banned and their Books destroyed. Writers who willingly flouted Maintainer standards could face severe penalties, including time in a Prison Age.
Once an Age's writing was deemed suitable, a Maintainer linked to the Age using an Environmental Verification Suit, or EV Suit for short, to verify the Age's stability. Only after such a thorough inspection, would a Maintainer’s Seal be applied to the Book, and travel permitted. Even so, regular Maintainer inspections were common.
The other role of the Maintainers Guild were similar in nature to modern day police and military. They were the only guild (as far as we know) permitted regular access to weaponry, such as rifles and pistols (although citizens could access daggers). It was the Maintainers who investigated crimes, captured the criminals and when tried, imprisoned them appropriately. A majority of these criminals would be sent to a prison controlled solely by the Maintainers, such as Irrat. If that was not suitable, if one had committed murder (rare in D’ni), for example, then they would be sent to a Prison Age.
While on Riven, Gehn recreated the Maintainers as one of the 5 Guilds of Riven. In an icon in the Beetle Room, the Guild is represented by a Maintainer attempting to stop a crowd of people from stabbing each other.
The Rivenese Guild had similar responsibilities with its D'ni predecessor, such as patrolling, maintaining order and security and perhaps guarding secure areas.