The AIC they're referring to is AIC 82/2003 (Pink 58) I would imagine. Register at
www.ais.org.uk and have a look since it's copy protected and I can't copy and paste it's contents...
The most pertinent point basically says that:
'no delay expected means: do not anticipate being required to remain in a holding pattern for longer than 20 minutes before commencing an approach'
The rest is mainly to get people thinking about how much fuel they should be arriving with in a busy TMA environment without, as far as I can tell, introducing any hard and fast rules in addition to standard JAR-OPS type fuel planning. So it doesn't provide any 'rule' as such as to how much holding fuel to carry, but could be seen maybe as gently suggesting that at least 20 mins might be a good idea
