How Do You Link A Press Release To A Previous PR?

In Semantic Mastery's weekly Hump Day Hangouts episode 243, one viewer asked how to link a press release to a previous PR.
The exact question was:
When linking a PR to a previous PR…. do you recommend linking to the BEST ranking (or MOST local) PR even it purges ORRRRRR….to link to the Press Advantage non-purging version of the release for most power?
