It uses [URI Fragment](https://en.wikipedia.org/wiki/URI_fragment) that agents (such as web browsers) never send to the server. Because of this, the url is fetched **without** the fragment parameters, unlike using query parameters.
The URI fragment follows [media fragments structure](https://www.w3.org/TR/media-frags/#general-structure). For example, one could use `t=number_of_seconds` to start playing a video at the specified position along with an extra [percent-encoded](https://www.ietf.org/rfc/rfc3986.txt) name-value pair separated by `&` char like `https://xyz.com/a-video.mp4#t=24&a%20name=a%20value`. **Notice the usage of `#` instead of `?`.**
Besides available w3c and proprietary URI fragment usage, nostr uses existing [NIP-94](94.md) tags as file fragment name-value pairs. NIP-94 event `.content` is equivalent to `alt` fragment field. For example, one could join the following strings to form an image url with inline metadata:
Multiple array values use repeated names and are positioned in the same order of ocurrence in the tag array. For instance, `["aes-256-gcm", 'i-am-a-key', 'i-am-an-iv']` becomes `aes-256-gcm=i-am-a-key&aes-256-gcm=i-am-an-iv`.
Metadata fragments are great for sharing urls with extra embedded metadata. They are also good for copying and pasting a resource's url from one note to a new one without losing its metadata.
But some clients can prepare image and video placeholders faster if specific fields are present outside of `.content`.
"content": "What a great place! https://xyz.com/example.jpg#m=image%2Fjpeg&dim=3024x4032&alt=A%20scenic%20photo%20overlooking%20the%20coast%20of%20Costa%20Rica&blurhash=eVF%24%5EOI%3A%24%7BM%7Bo%23*0-nNFxakD-%3FxVM%7DWEWB%25iNKxvR-oetmo%23R-aen%24`",
Also, some event kinds other than kind 1 and kind 30023 may have been designed with urls inside tags instead of in `.content`. For these cases, use `resource` tags (or `r` tags if it needs to be indexed by relays – in this case, metadata fragment keys and query parameter keys SHOULD be arranged in ascending order).
### Tag Examples:
A kind 30023 event JSON file (with `nostr/30023` MIME type):