In 100 Rogues, is it possible to sell items?

I've found several item shops, and I can purchase the available items with the gold I've found. I don't see a way to sell the items in my inventory. Is it possible to sell, or should I just discard them as my inventory gets full?

Assuming there's no way to sell, is this normal in roguelikes, or it a peculiar 'feature' of 100-rogues?

It is not possible to sell items in 100 Rogues, and it seems it never will be.

As badp mentions, Dungeon Crawl doesn't allow item selling, and that game is one of the primary influences for 100 Rogues.

(Source)

Some roguelikes like Dungeon Crawl do not allow selling items to shops:

Another basic design principle is avoidance of grinding (also known as scumming). These are activities that have low risk, take a lot of time, and bring some reward. This is bad for a game's design because it encourages players to bore themselves. Even worse, it may be optimal to do so. We try to avoid this!

This explains why shops don't buy: otherwise players would hoover the dungeon for items to sell.

_{from the Philosophy section of the ingame manual (press ?N).}

Most, however, do. Nethack's shop system is quite complex, for example. It supports credit, debit, stealing, restocking...

Yep, you can't sell items at all in 100 Rogues. Another note bout items is that beginning with Version 2.1, the item locker will always appear during the Dark Pope boss stage fight. Other appearances will be less predictable.