Many commands in PostalCAD are companions to one another.  A great pair of tools is the "Unlock All" and the "Relock" commands.

If your drawing has several layers that are locked and you need to edit anything on those layers you would obviously need to unlock them.  By typing in UA, for "Unlock All", all layers in the file will be automatically unlocked.  You can then edit any items you need to.

The companion to the "Unlock All" command is the "Relock" tool.  Type RL at the command line to relock any layers that were unlocked by the "Unlock All" command.  This is much easier than trying to scroll through the layers in a pull-down to find the locked ones, unlock them, and then scroll through a second time to relock.

Don't forget that the relocking tool only works as a companion to the "Unlock All" command in the same drawing session.  If you close the drawing and save any changes, the utility won't know which layers to relock when the file is reopened.  You would have needed to save a layer state to restore the locked layers.