What does it mean to be a member of a professional association in our field?

In July 2025, I posted a tentative message to the LTEST-L listserv with the subject title “Initiating a conversation about what it means to be a member of a professional association in our field.” My message provoked several positive responses, both on- and off-list, from individuals keen to take part in such a conversation. One such response came from the Language Testing Editors, Talia Isaacs and Xun Yan, who kindly invited me to submit my thoughts and suggestions in the form of a Letter to the Editor to encourage wider dissemination and discussion. What follows in this letter is based largely on my original LTEST-L post, but it also includes some additional comments informed by subsequent conversations with colleagues, together with a few practical suggestions for action.