The following are snippets of Peering Policy Clauses found in the Peering Rules of the Road - A Brief Study of Peering Policies study.  Clauses were categorized and put into rough categories for comparison.

Here are the clauses we categorized as requirements for Hot Potato, Best Exit, Shortest Path routing.

Excerpts from Peering Polices

Hot Potato Routing/Best Exit/Shortest Path and MEDs

2.4 Hot-potato routing is implied (i.e. we will not send or honor MEDs).—AboveNet

Each Internet Network shall implement "shortest exit routing" and advertise routes consistent with that policy, unless both Internet Networks mutually agree otherwise based on special circumstances. – Verizon

Each Internet Network will implement "hot potato" or "closest-exit routing". – ATDN

All peers will be configured for closest-exit routing unless otherwise expressly agreed. -- RCN

Each Internet Network will implement closest-exit routing, if not otherwise agreed. – LambdaNet

Each Internet Network shall implement "shortest exit/hot potato routing" and advertise routes consistent with that policy, unless both Internet Networks mutually agree otherwise based on special circumstances. – Highwinds

# Implement "hot potato" or "closest-exit routing." – Highwinds

Must advertise/implement routes consistent with "shortest exit routing", unless agreed to in writing – Charter

Existing peers whose in: out ratio rises above 2.00:1 will be expected to work with AT&T to implement best-exit routing or to take other suitable actions to balance transport costs. – AT&T