/// is found, \c NULL is returned.
///
/// This method's implementations currently are not specified to
- /// handle \c RRTypes such as RRSIG, NSEC3, ANY, or AXFR.
+ /// handle \c RRTypes such as RRSIG and NSEC3. RRSIGs are attached
+ /// to their corresponding \c RRset and it is not straightforward to
+ /// search for them. Searching for RRSIGs will return \c false
+ /// always. Support for RRSIGs may be added in the future.
+ ///
+ /// Non-concrete types such as ANY and AXFR are unsupported and will
+ /// return \c false always.
///
/// \throw RRsetCollectionError if find() results in some
/// implementation-specific error.