Trinity

1. If you ASK BIRD WOMAN ABOUT TRINITY you get the game credits. They really need a screen width of at least 77, but if your screen width is 62 to 76, then version 11 shows the credits anyway, writing off the edge of the screen with garbled results. If the width is less than 79, then version 12 responds, "The bird woman just smiles." Similar things happen with the undocumented command $CREDI.
2. In both versions, if you PUT POCKET UNDER WATCH you get, "The your pocket slides off the wristwatch and lands at your feet." Your pocket doesn't show up in the description of that location, but you can't interact with it or its contents elsewhere. If you take inventory you suddenly have your pocket again. You can do the same thing with HAND or FOOT but you apparently can't get them back. If you PUT ME UNDER WATCH, then "yourself" shows in the description. You can also do it with NORTH, etc., and "a direction" shows in the description. If you're wearing your watch and you PUT WATCH UNDER WATCH, then your watch drops, and if you pick it back up you're still wearing it. You can also use BEHIND instead of UNDER. The same thing happens if you EMPTY any of these objects INTO WATCH. A number of other objects work in place of WATCH. You can drop these objects out of sight by replacing WATCH with DISH or CHASM.
3. In both versions, you can drop objects you aren't carrying, using PUSH them UNDER WATCH. You can PUSH UMBRELLA or BALL UNDER WATCH to remove it from the tree, after which the location description includes, "A [garbage] is wedged in the branches overhead."
4. In both versions, when the bag still has crumbs in it, you can't PUT anything IN BAG, but you can EMPTY POCKET INTO BAG, putting things in it. When the bag is emptied of crumbs, everything else in it also disappears. EMPTY POCKET INTO UMBRELLA similarly puts objects "on" it.
5. In both versions, at The Wabe or Vertex, when the gnomon is screwed into the hole, the word THREAD is interpreted as referring to the lump of metal, and you can interact with it as if present. After you've cooled the lump, GET THREAD at Vertex picks it up regardless of where it is. --r_f
6. In both versions, if you have the splinter, SHINE (with no object) says, "The splinter illuminates the [garbage] rather poorly."
7. In both versions, if you DROP WEST (or another direction) you get, "You'd have to take the direction off   ROUND POND first." in the Infocom interpreter. Frotz says "object#143" instead of "  ROUND POND".
8. In both versions, EMPTY TREE or GET something FROM TREE tell you "the tree isn't long enough to reach" the object in the tree.
9. In both versions, if you don't have a key, and you're at a closed white door, LOCK DOOR says, "The your hand won't lock the white door."
10. In both versions, there is a difference between putting things IN and ON the lump of metal. If you PUT the umbrella or spade ON the lump, you're told, "You feel a strong magnetic attraction.", but you keep the object. If you PUT a paper item such as the bag of crumbs or crumpled piece of paper ON the hot lump, it burns up. But you can PUT any of these things IN LUMP without anything special happening. Also, PUT GNOMON ON LUMP says it "attaches itself to the" lump "with a sharp click." even if it already has enough contents that PUT GNOMON IN LUMP doesn't work.
11. In both versions, at South Bog, SMELL says, "The flytrap's smell reminds you of corn syrup.", but the flytrap is at North Bog, where SMELL doesn't mention it. --Torbjörn Andersson
12. In both versions, at Ossuary, ENTER BARROW says, "The slopes around you are too steep to climb", but you can go SOUTH to get there. --Torbjörn Andersson
13. In both versions, when you have honey on your hand, PUT HAND IN WATER washes it off in the cauldron or the stream, but not in the lagoon, soapy water, or reservoir. --Torbjörn Andersson
14. In both versions, if you put the paper bag in the reservoir, or fall in carrying it, its contents are moved to the soggy bag, which replaces it. If instead you enter the reservoir carrying the paper bag, it is replaced by the empty soggy bag--its contents disappear. --Torbjörn Andersson
15. In both versions, even if the walkie-talkie is dripping wet and not working, TURN OFF RADIO says it falls silent. --Torbjörn Andersson
16. In both versions, at Shallow Crater, EXAMINE ROAD says, "The paved road leads northeast towards the tower, and southeast into the desert.", but the tower is actually to the northwest. --Torbjörn Andersson
17. In both versions, CLIMB OVER TRELLISES says, "The trellises is too high." --Torbjörn Andersson