What's the 6 object? (also, bug report)

[Grotug]

I've been killing off a lot of hobbit warriors lately. My latest one was searching out a 6 object on DL5, and the level has quite a few candidates for good objects found. That said, I didn't think the spear of lightning would generate a 6 (maybe a 3 or 4?) nor the main gauche of acid @ also found, nor the maul of slay troll (yes, all three on the same level). So I kept on looking... during my search @ ran out of light and discovered that he cannot read scrolls by the light of other humans in the dungeon, which seems like a bug to me. Light 1 is Light 1 regardless of where the light is coming from, no? I mean, I can read scrolls in lit rooms when @ has no light source.

https://youtu.be/-XfELhOmT60#t=3m56s

@ did end up finding the 6 object, and as suspected it wasn't any of the three weapons found, nor was it the sling of power (+9, +17). I'm pretty sure it was a staff of teleportation. It's rare a good LF results in finding so many useful items on a level, but I was glad that my persistence paid off! Maybe I won't kill this hobbit warrior off so carelessly.

How do I know the 6 feeling wasn't the sling? Slings of power are found at quite a low depth (I've found them on DL1 with 3 feeling), whereas _Teleportation is native to the DL20s. I've also experienced relatively high LF on early levels that had _Teleportation in the past.

[Thraalbee]

My understanding is that the 6 is based on the total value of items rather than a single. Also, sometimes a squelched dungeon book is the culprit