In Jira, each Project has an alpha prefix. For instance, if a project is called Development then it could have a prefix called DEV. This is generally chosen when the Project is created. For Wekan, we can have a randomly generated board prefix that takes into account existing prefixes in the system and is auto-generated from the name of the board (such as "Development" automatically suggesting the prefix be "DEV"). This could be called the "Board Key". This will be helpful for building a Task ID feature that can be used for "Issue Number" referencing by users throughout the system. Otherwise known as a "pretty ID". For instance, each new card would be:

DEV-1
DEV-2
DEV-3

Etc...

This would allow people who are referencing issues to talk about them by this easier to remember moniker.