Scenario: A teacher has been standoffish towards me since day one. Teacher starts being friendly with me. Teacher then asks if I know of a particular resource to help with reading. I share resource and train teacher on how to use it. A few days pass. Teacher sends out mass email sharing said teacher's "discovery" on this resource and how teacher would love to train people on it. Principal then replies with a mass email praising teacher and saying we should all take heed from this teacher's example. Teacher has gone back to being unfriendly. tl;dr: Colleague essentially takes resource I shared and takes credit for it. How would you feel? I don't have a problem with the teacher sharing the resource or wanting to train people on it. I just think the proper etiquette/decent thing to do would be to say "I found this great resource from ________ and wanted to share it with everyone" instead of "I discovered this great resource.."