Best Practices
Tier 1
What your network is, and the other fellow's is not.

Tier 1 is a very loosely defined jargon term intended to position the described network at the top of the similarly loosely defined network hierarchy of the public Internet.

Some people assert that it's more a marketing term than an engineering one these days; much heat, and occasionally some light, accompanies the cyclical discussion of the topic on the NANOG mailing list.