Updated: Sep 4
Item tags are slips of paper that indicate an item that exists in game. They may or may not have a "physical representation" prop, also called a "phys rep" or "rep" for short. Not all tags require reps, but some specifically do as stated in the rules. Conversely, not all props/reps require tags, except some that are stated in the rules.
Any rep with a tag can legitimately be stolen in game as part of play, with a few exceptions such as soulbound items. If weapons, shields, or armor reps are found without a tag attached, then it doesn't exist in the game and cannot be stolen. You should leave it where you found it in that case. Taking something without a tag affixed is just plain stealing. Underworld has a zero tolerance policy for real thievery. If you plan to steal items in game, be sure you know the rules for stealing and robbery before you begin.
Anatomy of a Tag
All Underworld tags follow the same format, though they may come in different sizes and layouts. Here is an example of a tag and how to read the information given to you. (This is a mockup of a basic item tag, not a real tag)
Common Tag Types
The most common items you will see tags for are weapons, armor, mundane or generic items, spell scrolls, and raw materials. The descriptions could be anything you, or a Shaper, dreams of. It might make sense, it might not. It might be fascinating to you, or it might be junk. It's up to you to decide what an item means to your character outside of its value to game mechanics.
All tags must be signed or stamped by a staff member. Any tag not signed or stamped is against the rules. Cheating by printing your own tags is unacceptable.
How to Make Your Own Tags
In order to make your own tags, you need to have a profession or trade. There are 2 categories of skills you can purchase with your Character Points (CP) that allow you to create tags yourself. Professions are Blacksmithing, Alchemy, Scroll Crafting, and Trapper. These skills use Raw Materials to produce items from the lists you can find in the Core Rulebook. Trades refers to the Tradesman skill, which is used to produce Raw Material (RM) tags. Your chosen trade will produce a certain number of materials per month, and you can call that job anything you like that feels thematic.
Fill in the tag request with any descriptions you think suit your character and your job. You can then submit your tag requests through the database and they will be printed and signed for you when you arrive at log.
Uncommon Tag Types
There are also some uncommon tags that you won't see at an average event or might need to do extra roleplay to find. There are many interesting things you can find in the world of Underworld. High level magic and crafting, such as Ritual Scrolls, Blacksmithing Artifice, and Chemistry are written differently.
Rituals are high level magic that only certain people have learned how to cast. They have a separate set of rules from regular battle magic and require the presence of a shaper. A ritual scroll will have the same basic format as any other scroll, with the addition of details such as RP instructions, a list of ingredients and props, and a number of "charges" the scroll can be reused for before its power is depleted and it vanishes.
Catalysts are fragments of magic contained in an item which exudes a certain type of power and emotion. These tags can easily be identified by a filled black circle in the center of the paper. They are the same size as your average item tag.
Artifice and Chemistry
Artifice and Chemistry are high level production types, similar to ritual casting for magic users, except that they are used by expert level blacksmiths and alchemists. The mechanics to use these 'Synergy' scrolls are the same, and you can read through the applicable rulebook in more detail.
All tags have value in the game, so don't forget to bring a pouch or bag to collect and carry your tags in. For some types that circulate often, like RM, some people like to use clear packing tape to laminate and protect them so they can be used over and over again.
Sometimes in the chaos of battle, you don't have a chance to look at what you've just looted from a monster and it's fun to rest in camp and count your tags to see how much richer you are now!