> ## Documentation Index
> Fetch the complete documentation index at: https://docs.seminode.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Tags

> Along with content, OMA events are tagged according to a convention for filtering and querying.

Tags are key-value pairs attached to events that nodes use for indexing and filtering. When a client queries a node (e.g., "give me all supply listings for part MAT-00042"), it filters by tags. Only single-letter tags are indexed by nodes, which is why OMA uses them exclusively.

All tags **SHOULD** be lowercase, with no spaces. All tags except `u` (UserPublicKey) are expected to have one value.

Format: `["<single-letter>", "<value>"]`

## Tag Reference

| Tag | Name          | Use                                                                                                                                                                         | Example                                                                                      | Notes                                                       |
| --- | ------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------- | ----------------------------------------------------------- |
| `a` | Address       | Referential address of an event for replacement, i.e. when a listing must be updated, it is done so on the address.                                                         | `["a","<kind integer>:<32-bytes lowercase hex of a pubkey>:<d tag value>"]`                  |                                                             |
| `d` | Identifier    | Stable identifier for a given material, this is a concatenation of material information that makes it *physically unique* among other components with the same part number. | `["d","MaterialNo + Supply + DateCode"]`                                                     |                                                             |
| `n` | MaterialNo    | Material/part number from your system.                                                                                                                                      | `["n","MAT-00042"]`                                                                          |                                                             |
| `m` | Manufacturer  | Manufacturer name.                                                                                                                                                          | `["m","Acme Corp"]`                                                                          |                                                             |
| `h` | Thread        | Groups related events.                                                                                                                                                      | A deterministic **thread ID** computed from the root `event_id` and two participant pubkeys. |                                                             |
| `y` | Type          | Material transaction type (e.g., `supply`, `demand`).                                                                                                                       | `["y","supply"]`                                                                             |                                                             |
| `c` | Company       | Event publisher namespace.                                                                                                                                                  | `["c","acme"]`                                                                               |                                                             |
| `b` | Batch         | Groups listings created by a single **publish action** (e.g., one API call or one file import).                                                                             | `["b","XYZ123"]`                                                                             |                                                             |
| `i` | InternalNo    | Internal ERP/DB tracking/reference.                                                                                                                                         | `["i","INT-7788"]`                                                                           |                                                             |
| `t` | Generic       | Free-form topic tag (search/filter).                                                                                                                                        | `["t","diodes"]`                                                                             |                                                             |
| `r` | Reply Node    | Websocket URL for reply events.                                                                                                                                             | `["r","wss://domain.seminode.com/inbox"]`                                                    |                                                             |
| `p` | Recipient     | Intended recipient's pubkey.                                                                                                                                                | `["p","<pubkey>"]`                                                                           | Exclusive to thread events of kind Quote, or Quote Response |
| `s` | Status        | Workflow state this event belongs to (e.g., `accepted`, `rejected`).                                                                                                        | `["s","accepted"]`                                                                           | Exclusive to thread events of kind Quote Response           |
| `z` | Finalized     | Workflow state this event belongs to (e.g., `pending`, `complete`).                                                                                                         | `["z","pending"]`                                                                            | Exclusive to thread events of kind Quote, or Quote Response |
| `e` | Event         | Reference to another event (mention/link).                                                                                                                                  | `["e","<event-id>"]`                                                                         |                                                             |
| `u` | UserPublicKey | User pubkey(s) associated with the event, allows fine grain filtering for company users.                                                                                    | `["u","<pubkey>"]`                                                                           |                                                             |

* **Example(s):** `["u","<hex>"]` (repeat tag if multiple)

## Query Modifying Tags

Query Modifying tags offer further specification for what events the client wants returned. These tags are not stored in events — they are passed in filters and modify the underlying query.

* **Match:** `"match"`  `<Optional["match", "fuzzy"]>`
  * Supports `"fuzzy"` for prefix or trigram matching on select tags. Useful for partial part number searches.

* **Intent:** `"intent"`  `<Optional["intent", "tail"]>`
  * Supports `"tail"`, which returns only the most recent event in a conversation between two parties for a given listing. This is useful for showing the current state of a quoting thread without returning the full history.
  * Determined by the most recent timestamp for a unique combination of the `"e"` tag (listing event) and an unordered pair of the event author and recipient `"p"` tag.