I saw on the livedocs site that there were some tags and attributes and attribute values that were deprecated as of MX7 but it did not list any that had dropped as of 8, are there any that I should be concerned about when upgrading from MX7 to 8?
You've probably seen this link. Since that's for Coldfusion 8, it would seem no. Newer versions of Coldfusion still support deprecated tags/functions, but they'll be no guarantee they'll work.
Comment