Level by LIFFY (or 10 before)
DFC, Fork handles and others;
In our (Shannon) MATS part 2 Co-ordination procedures we have a Letter of Agreement (LOA) with each adjoining centre. Each LOA defines minimum radar separations for silent handovers, reduced separations etc. Included in the LOA for London are level restrictions for most EGxx ADES's.
London sets these levels, off hand they include:
LIFFY (any ADES in MAN/IOM area) max FL270 e.g. EGCC, EGBB
LIFFY some Northeastern ADES can have FL330, I think EGNX, EGUN etc.
STU/EVRIN
Any EGLL TMA Max FL330
Simultaneous OPS through STU and EVRIN(UL607) are allowed providing
1.Both are EGLL TMA inbound or
2.Both are overflyers
3.If one is inbound and the other overflying then the inbound has to be through EVRIN
STU Cardiff and Bristol max F310
BANBA Southbound DEPs from EIDW Max 270, EICK UB10 max 250
Thers are others, but LIFFY is a special case. Over DUB VOR we are trying to accomodate EGAx inbounds descending to F250 and in transfer to EIDW,
EGCC etc. inbounds descending to F270 and in transfer to MACC (anything higher and still descending has to be co-ordinated with EGTT sec 7, Outbounds from EGCC climbing to F280 looking for higher but have to co-ordinated with EGTT sec 7 before RAMOX. EGAx deps climbing to F240 looking for higher. Scottish TMA inbounds descending to Max F320.
East Midlands etc, inbounds descending to F330, Scottish TMA outbounds, climbing to Fl310 looking for higher.
And of course there's always some other looney doing something different in the mix, like RVSM excempt state a/c or SST trials in the Irish sea to complicate it further.
While I appreciate these things don't all happen at the same time It's not uncommon to have 6 or 7 a/c crossing in 3 dimension within 5 miles of DUB VOR.
Best practice should be common practice this is why the work is done early. A/c have to be level before transfer to another sector unless otherwise co-ordinated.
Thorisgod