Online discussion list or discussion forum
Family name, INITIAL(S). Title of message. Date added. Discussion group title. [Online]. Year. [Date accessed]. Available from: URL
Example:
Stubbings, R. Diagnostic tests. 3 August. Lis-infoliteracy. [Online]. 2005. [Accessed 18 August 2017]. Available from: http://www.jiscmail.ac.uk