When the "Enable Keyboard Shortcuts" option is enabled, one can press ? to open the shortcuts menu or press other keys to open submenus. Those menus display the available keys and their corresponding description/action.
For example, pressing M while on a post's page opens the following submenu:
Now, while on that menu, pressing I opens the following submenu:
As you can see, the T key is missing a description.
Pressing it navigates to the post's timeline, so, I would imagine it should be:
An alternative solution would be to get rid of the "post issues" submenu altogether (since it only contains one item) and replace it with "T timeline". I actually prefer this option because "post issues" isn't very descriptive (that's unless there are plans to add more items to it or if there are already existing ones that I don't have enough privileges to see).