From current DINs. Sorry. Blame it on an RN Warrant Officer who used to work in London booking flights for all London personnel. Put his Air Miles card on every single booking, charged with fraud.....
h. Complimentary vouchers. Crown servants travelling by air on Government business, paid for from public funds, must not make private use of frequent flyer bonuses that arise as a result of that expenditure
e.g. Air Miles, two-for-one or companion tickets, or equivalent schemes. They may, however, collect such bonuses to enable them to use the associated benefits (e.g. priority booking, special lounges) in respect of
official travel. The receipt of any benefits accruing from official travel must be recorded in Hospitality Books (see paras 12 - 14) which should be annotated to show that the bonuses have been notified to the Budget
manager, against the possibility that they may be used at a later date for official purposes. In the case of gifts or benefits given for using particular modes of transport, it is important that the mode of transport should be
chosen in accordance with Departmental guidelines on economy, and that a decision to travel in a particular way should not be taken in order to qualify for such gifts.