It support hyphens and underscores.
- prefix-name
- prefix_name

For Chrome: https://chrome.google.com/webstore/detail/slack-channels-grouping/lcbnhfianneihfgkmfncnhpkpghedbkm

Source: https://github.com/yamadashy/slack-channels-grouping

Install

• License: MIT License
• Weekly downloads: 1
• Average daily users: 119
• Rating: 5/5 of 2 ratings
• Created: 2019-02-06 16:46:35
• Last updated: 2020-05-09 14:55:12
• Homepage: https://github.com/yamadashy/slack-channels-grouping
• Support site and email
• Orig: https://addons.mozilla.org/en-US/firefox/addon/slack-channels-grouping/
• API: {24d54390-97ea-4c57-b4be-7e32232ca609}