mr:tldr:0e556

This command appears to be written in a Unix shell script language, where mr is most likely a custom script or an abbreviation for a specific command.

Explanation:

• mr is likely the name of a script or a command that performs some actions.
• -j is an option or a flag that is being passed to the mr command. The purpose of this flag depends on the specific implementation of the mr command.
• ${5} is the syntax for accessing the value of the 5th command-line argument passed to the current script or command. This assumes that the script or command is being executed with command-line arguments, and the 5th argument holds a specific value required by the mr command or script.
• update is an argument that is being passed to the mr command or script, specifying the action or task to be performed. The meaning of update depends on the implementation of the mr command.

In summary, this command is invoking the mr command or script with the -j flag and passing the value of the 5th command-line argument as well as the update argument. However, without specific knowledge of the mr command or script, the full functionality and purpose of this command cannot be determined.