I find it is hit and miss. Some agents will announce, for example "F, C, Star Gold, Star Silver" some will say "F, C and Gold Card holders"(ie: no silver) and some will just use their own airline's elite levels, eg for a UA flight "F, C, Global Services, 1K, Premier Executive and Premier members.." so there's no real standard. Seems to be up to the gate agents - though I imagine all airlines have seating priorities (such as UA's group system, LH's Zones, etc). Some airlines (SQ is good at this) ignore a call for any kind of elite levels and as others have said most short haul flights in europe (specially LH!) just call for boarding and then you jam in with everyone else...