change tags to support multiple values

18.md

@@ -53,19 +53,23 @@ Transport specifies methods for sending the ecash to the receiver. A transport c
 
 - t: type of Transport
 - a: target of Transport
-- g: optional tags for the Transport 
+- g: optional tags for the Transport
 
 ### Transport types
 
 The supported transport types are:
 
+### Tags
+
+Tags are an optional array of `[tag, value, value, ...]` tuples that can be used to specify additional features about the transport. A single tag can have multiple values.
+
 #### Nostr
 
 - type: `nostr`
 - target: `<nprofile>`
-- tags: `[["m", "NIP-04"],["m", "NIP-17"]]`
+- tags: `[["n","04", "17"]]`
 
-The `m` tag MUST specify at least one type of Nostr direct message type the receiver supports. For [NIP-04](https://github.com/nostr-protocol/nips/blob/master/04.md) and [NIP-17](https://github.com/nostr-protocol/nips/blob/master/17.md) direct messages, the sender sends a `PaymentRequestPayload` as the message content. 
+The `n` tag specifies the NIPs the receiver supports. At lease one type of Nostr direct message MUST be specified. For [NIP-04](https://github.com/nostr-protocol/nips/blob/master/04.md) and [NIP-17](https://github.com/nostr-protocol/nips/blob/master/17.md) direct messages, the sender sends a `PaymentRequestPayload` as the message content.
 
 Note that the use of NIP-04 direct messages is strongly discouraged, since it reveals metadata about sender and receiver public keys.
 
@@ -104,4 +108,4 @@ _Example_
 creqAaVhQRVhVWNzYXRhTXgiaHR0cHM6Ly9taW50Lm1pbmliaXRzLmNhc2gvQml0Y29pbmFEeCNQbGVzYXNlIHBheSB0aGUgdmVyeSBmaXJzdCBjYXNodSBwcmFUgaJhVGVub3N0cmJUYXhGbnByb2ZpbGUxcXFzZG11cDZlMno2bWNwZXVlNno2a2wwOGhlNDloY2VuNXhucmMzdG5wdncwbWRndGplbWgwc3V4YTBrag
 ```
 
-[00]: 00.md
+[00]: 00.md