"Vendor Trash" is a universal term used in MMORPGs to describe an item that has no use other than selling it to a vendor. Some items are made specifically to be vendored for money but other items at one point in time were useful but have since become out dated with time and are not used for anything useful anymore. Despite the general term used for these items, it is actually very important that you loot any of the vendor trash you come across and... well, vendor it!
As someone who is consistently rich in every MMORPG that I play, I can tell you with certainty that looting the vendor trash is one of the most important things you can possibly do to make money. There are some people who don't loot the vendor trash from mobs and these are the players that are constantly poor and can't even afford their own spells. Usually this is annoying knowing that someone is so stupid and you can't convince them otherwise but in EQ this is actually quite beneficial. Since after a certain amount of time anyone can loot the mobs they leave behind you can easily make thousands of plat just following someone around looting everything they don't.
Anyway, we're getting kind of off topic. For new players sometimes finding what items are "vendor trash" can be somewhat difficult. Everquest has tens of thousands of different items and it can be quite confusing figuring out what is worth keeping and what is worth trashing. On most of the Farming and Leveling guide pages I list a few of the items at each location which are Vendor Trash and link to this page, making it quite obvious what those item's uses are. However below I am going to try and give you an idea of what to look for in determining an item being vendor trash.
When you right click and hold over an item it wil bring up a description window for that item. What it says in this window will be key for determining if an item is vendor trash or not. Here are a few of examples of items that are vendor trash and I explain why and how I figured out that they are.
The way you can tell the two items above are Vendor Trash is that upon inspecting them you will notice that they don't have anything on them that says they have any use at all. Normally below where it says "Modified" you will see information about the item such as "This item can be used in Tradeskills." (an example is in the picture below). But these items say absolutely nothing there. This is a dead give away that these two items serve no purpose aside from Vendor Trash.
Now just because it doesn't say anything here doesn't mean that is the only way to distinguish what is vendor trash and what isn't. Certain items will say something down there or actually appear otherwise useful but still be considered Vendor Trash. Certain items you will have to use your best judgement on to determine if they're vendor trash or actually worth trying to sell in The Bazaar. For most locations in my leveling and farming guides I have listed a lot of the vendor trash items and link them to this page, this will make it much easier on you to figure out what's trash and what isn't. However I am going to give you a few examples below just to help you be more self reliant when figuring things like this out.
Let's take a look at two more items that are considered vendor trash but aren't like the items shown above.
Both of these items come from PoP (Planes of Power) zones and used to play a major roll in acquiring gear from questing during that expansion. So, what I mean by that at one point in time they were not vendor trash items but now that the game is a dozen or more expansions past PoP the gear that these used to be used in acquiring is now obsolete and no longer worth going through the trouble of getting, making these items now vendor trash.
Of course without knowing that little bit of information you may think that these items still have a use, since they say "This item can be used in tradeskills." on them. Luckily that's what this page is here for, ultimately if the item links you to this page it is under 99.99% of circumstances, vendor trash. The only ways it might not be vendor trash is if you're trying to collect the items for the old gear to hang up in your house or something or if you're playing on the Progression Servers at the time of whatever expansion the item may still be useful in. Otherwise, you've got it, trash!