Hi @CmdrMichael,
Thanks for your note.
At the moment, this feature does not exist in Mattermost.
Could we have your help looking at these feature requests which seem similar? You have 10 votes to up-vote the suggestions you would like to.
1. https://mattermost.uservoice.com/forums/306457-general/suggestions/18623266-team-initials
2. https://mattermost.uservoice.com/forums/306457-general/suggestions/15465123-team-icon
Let me know if this helps?