The phrase "at authorisation" is correct and usable in written English.
It can be used in contexts where you are referring to the point in time or condition when something is authorized or approved.
Example: "The project will commence at authorisation from the board of directors."
Alternatives: "upon approval" or "at the time of authorization".
The 1999 festival is also remembered for the Manic Street Preachers requesting and being given their own backstage toilets; however, it was revealed by the band that this was a joke - the "reserved" sign on the toilet was not at the authorisation of the management.
The public was also advised to verify that these products were assessed by Health Canada for safety by looking at the authorisation number printed on the label.
This 25-year product – Genie – received FSA authorisation at the end of September last year.
So intimidating were these attacks, so high profile were they, that they cannot have taken place without authorisation at the very highest level".
The level at which the authorisation can be given is lower than for intrusive surveillance and the confirmation of a surveillance commissioner is not required.
Britain and France have summoned the Israeli ambassadors to London and Paris in protest at Israel's authorisation of 3,000 new settler homes in the West Bank and East Jerusalem.
After the American attack on Afghanistan, al-Qaeda's foot-soldiers have reportedly been given the green light to attack "targets of opportunity" without authorisation at the highest levels.
Chilcot also found that the decision to go to war was taken before "peaceful options for disarmament had been exhausted", in particular that diplomatic overtures to secure a security council authorisation at the United Nations had not been extinguished.
The new rules would subject novel food to a safety evaluation and authorisation at the EU level.
The Rebels' system of vouching for attendees is a way of authorising who can be at the meeting and authorisation is an important part of any secure system.
