The term "Pending Clearance" was first published in an AIP Supp, probably around 1999, when new airspace and radio procedures were being adopted. The Supp has been cancelled and thus the term should not be used. Try writing to Airservices, not me, if you want a copy.
The AIP Supp also had other recommendations to minimise radio chatter, such as, no need to say "Standby for departure" at the end of an airborne report when initiating a SARWATCH (when comms on the ground are not available). Funny how we have come full circle and seem to have more radio chatter, especially at a non-towered aerodrome.
I am lead to believe that AIP Supps are not issued with Jepps.
Do Jepps user have to download AIP Supps from Airservices?