URL query parameters

URL query parameters interpreted by the platform.

Caching

Instruct the visitor's browser to cache a request "forever".

The way it works is that several HTTP headers will be included in the response that tell the browser to cache this request for 30 years or so. It is still the browser's choice to cache the request or not. For example, browsers might decide not to cache it if the visitor doesn't have enough disk space.

Note: the URL will be cached for virtually forever, there is absolutely no way to undo this. The only way to force the browser to reload the resource is by changing the o1-cache parameter, in which case we are technically talking about a new URL, thus a new resource. The old request will still remain being cached indefinitely.

https://example.com/path?o1-cache={o1-cache}

o1-cache

A unique identifier, typically a hash derived from the content that is being requested. To make the browser reload the resource, you must provide a new o1-cache value.

You can use o1-cache=1 if you want, but in that case changing the resource on Boomla will not automatically force the visitor's browser to reload it, you would have to manually increment it to o1-cache=2. Up to you - but I certainly recommend you use the hash of the relevant resource, or just a part of it, for example with:
img.fileHash().substr(0, 10).