The resource search pages, e.g. https://build.fhir.org/device-search.html, as well as the search parameter section of each resource's main "content" page, should include mention of the SearchParameter registry.

Consider adding a statement along the lines of "Additional search parameters, and search result modifiers, that apply to all resources, are documented on http://build.fhir.org/search#all and http://build.fhir.org/search.html#standard