No Arty Spam : Host is NATO
No Inf Spam : Host is PACT
No Tank Spam : Host is NATO
Maximum Lvl X : Host is Lvl X
The maximum level is really pointless, level does not say anything at all about your skill level, but a lot of hosts does not seem to understand that. A high level means you may have unlocked a lot of units and (should) have some experience but you can have lost every game up to where you are now. And since some people never play ranked, they might not have a ranking. And since you can unlock enough units for a decent deck just by playing the campaign, level does not matter that much in that aspect either.
If people truly fear to meet players that might be better than themselves, a more serious way to display a hint of your skill level would be to show a players % win/loss, average score or something similar. Like in starcraft (looked like 1-4-3, wins-draw-losses). Gave you an idea what kind of skill you were up against, but you had no idea of the quality of the opponents in those scores. Level alone means nothing.