Messages
Similar to backups you might only realize that you needed some data until it is no longer accessible. There might be knowledge stored in SlackSlack Slack is a Collaborative Group Chat Platform https://slack.com/. The WordPress community has its own Slack Channel at https://make.wordpress.org/chat/. for you that we recommend you to take a look at so that you can ensure it is not left behind in the move.
Public Channels
We have migrated all history of all channels on the WordPress Slack server. Typically, the name of the channel on Slack is the same on Matrix. So #core is #core on Matrix. If you want to access the rooms from another homeserver, you need to append our homeserver name, so the example from above becomes #core:community.wordpress.org
When you log in to Matrix, you should already be a member of all room equivalents to the Slack channels you took part in.
DMs
Due to the private nature of DMs, we have not been able to migrate them for you. If you have been using Slack DMs, we recommend that you go through the list of your DMs to see if you find something you want to preserve:
As a solution to save your DMs for yourself, you can access Slack through a browser and use an extension (like Rob/SI Slack Channel Exporter or Slack Channel Exporter) to export them.
You can restart the DMs with the same people on Matrix. You could decide to repost the old messages (as a single message authored by yourself) manually for searchability.
Organizing your rooms on Matrix
Different clients might have different ways of organizing rooms. There is one organizational tool built into Matrix that is called Spaces (supported for example in Element, Cinny or Nheko) where you can group rooms according to your needs. See our guide on how you can do this.
Furthermore Element has ways to mute a channel by making it “low priority” and sorting the room list by people and alphabetically or last activity. See our Element guide for more information.