Sylladex



Captchaloguing is when items in Homestuck are put into John's inventory, which is called the Sylladex. John himself originally had no idea as to what this meant. When an item is captchalogued, it is put onto a Captchalogue card and added to John's Sylladex. John started with four captchalogue cards in his Sylladex's Captchalogue Deck. He currently has five captchalogue cards. The ways in which John can interact with the items captchalogued in his Sylladex are dictated by his Sylladex's current Fetch Modus. Fetch Modi can be switched between if the Sylladex has more than one Fetch Modus card available to it. Additional Captchalogue Cards can be added to a Sylladex.

Stack
John's first Sylladex Fetch Modus, signified by a bright magenta Sylladex and matching Captchalogue cards. His Captchalogue cards are arranged in a stack, and he can only use or otherwise interact with the one at the top of the stack. He can also combine that card with the previous card if doing so is logical, or use it with the previous card. If he picks up an object while his Sylladex is full, the item at the bottom of the stack will be dropped. However, if he attempts to take an item which logically goes with the object at the top of the stack, he can choose to combine them together immediately, even if he has no free Captchalogue cards. Items which can be combined can be combined across other items if it's physically possible for the items to become lodged within the resulting combination, for example the Red Package, the Sburb Beta, and a PDA between two cakes.

A new Captchalogue Card can be added to a Sylladex with the Stack Fetch Modus simply by pushing it out of the stack.

John finds his Stack Fetch Modus card under his Magic Chest after tentacleTherapist moves it using Sburb.

Queue
The second Fetch Modus John obtains, signified by an orange Sylladex and matching Captchalogue cards. It is essentially the opposite of the Stack, in that only the card at the bottom of the deck (the one that was added before any of the others) may be used directly. It also propels the items that are pushed out of the deck faster. Otherwise, it behaves identically to the Stack.

John finds the Queue Fetch Modus card in a copy of Data Structures for Assholes.

Hash Map
turntechGodhead's Fetch Modus. Hash maps work through a key-to-value lookup structure, therefore suggesting his inventory works as a traditional one, with each artifact readily available. This is presumably the most powerful Fetch Modus, assuming a good hash function is used.

Trees
tentacleTherapist's Fetch Modus. She claims it isn't exactly practical but she thinks it is elegant.

Strife Specibus
Items can also be placed into the Strife Deck of his Strife Specibus, where weapons are kept. The Strife Specibus uses special green Captchalogue cards, of which John started with one. As with normal Captchalogue cards, more may be collected. When John first added an item (the Hammer), he had to select the appropriate Kind Abstratus (specifically, the Hammerkind Abstratus) from the back of the Strife Specibus. This turned out to be permanent, meaning that John can only wield hammers for the rest of the game.