(These instructions are also covered in an instructional video on YouTube...)

You need someone in your org with rights to create github repos.
Create a (probably public) github repo. Name it something like <your-group-abbrev>-terms. Whatever you choose for <your-group-abbrev> will become a tag that applies to all terms in the repo/wiki.
Turn on the github repo's wiki feature. (Settings > Options > Features; tick Wikis)
Turn off most of the other features; you won't need them. (Settings > Options > Features; untick other stuff)
Configure permissions and/or contributors. (Settings > Manage access)
Add at least one term to your wiki. (Wiki > New Page; copy the template from here and fill it out.)
Share the URL of the repo's wiki (NOT the URL of the repo itself, but <repo> + /wiki; THIS is where you want people to go to use the wiki).
Consider registering your wiki with the CTWG so the world can discover it (see "Registry of Terms Wikis" here).
Configure your repo to publish a glossary.

Note: a Term Wiki is a place where you can develop the terminology that is specific to the needs you have for serving some purpose(s). The wiki should not serve as a glossary; glossaries are to be generated from wiki content.

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