Is this possible?

[asdu]

Does Crawl have a way of assigning a permanent identifier to an object? Angband & sons iirc have something like this: you can inscribe an object with a number and from that point on you can use that number interchageably with the letter identifying the object. I.E. you inscribe your potions of healing with 1 and make a macro to drink a "1", and it will always make you drink a potion of healing no matter how much you switch around your inventory.
The reason I'm asking is that I'm playing a vampire necromancer and I often use sublimation of blood on my potions of blood, which generates potions of decay which I then have to dispose of, but obviously their letter changes all the time and that annoys me to no end

[Kate]

You might be able to achieve something helpful with autoinscriptions. What you can't do is use them to permanently identify an item (for example, if you inscribe a scroll that you know is enchant armour with "ea" and drop it, the next enchant armour scroll you find will won't have that inscription).

However, the manual's section on inscriptions is here. To take your example, you could add some lines to your config like "autoinscribe = potion.*healing:@q1" and then typing q1 in-game would quaff a potion of healing. "autoinscribe = potion of.*blood:@*2" should inscribe all your potions of (coagulated) blood with @*2, meaning you can wield them for sublimation with w2, quaff them with q2, etc.

Annoyingly, the drop command doesn't seem to work with these inscriptions, probably because d then a number is already used to select the number of items to drop from a stack. Maybe there's a way the interface can be improved to make this possible.

Edit: Oh, another possibly easier way to get rid of your decay is with the drop filter - if you press , on the drop screen it automatically selects all the useless items in your inventory to be dropped, which includes potions of decay. There's another problem with this, though: as a vampire, some items are useless when you're low on blood but not at all useless when you're full (such as rings of poison resistance, potions of berserk rage). The drop filter will try and make you drop those items too, if you use it while low on blood. This might be a bug, I'm not sure - you could get around it by manually inscribing things you're sure you won't want to be automatically dropped with !d, and then the drop filter will skip them.