Web pages/services which can be displayed without
using any linking information.
Linking Parameters
The linking parameters are those fields that specify the particular
entries that the user might be interested in at the remote
site. E.g., if the user wants the Abstract for a particular
bibcode, then the bibcode is the linking field. If the user
wants a DSS overlay of the region surrounding an object, then
the position or target name will likely be the linking field.
Some representation of the link field will normally be
encoded in the returned URLs.
Search Parameters
The search parameters are used to determine which services
to be retrieved, but typically are not part of the specific
URLs generated. These generally refer to metadata about
the resource, i.e., the kinds of data stores.
Control parameters
The control parameters affect how the registry service itself
is to behave. They may be set to truncate the list of returned
URLs, and or to request that the registry get information
about each URL, e.g., the number of anticipated hits for the
specified link parameters.