The display options customize the behavior of the @display command to your particular taste. The first form of this command displays all of your display options. The second form displays just that one option, one of the flags listed below.
The remaining forms of this command are for setting your display options:
@display-option +<flag>
@display-option -<flag>
@display-option !<flag> (equivalent to -<flag>)
These respectively set and reset the specified flag
-blank_tnt Show the verb args on all verbs.
+blank_tnt Don't show the verb args on `this none this' verbs.
-shortprep Use full prepositions (e.g., "on top of/on/onto/upon")
+shortprep Use short prepositions (e.g., "on")
-thisonly Specifying . (:) to retrieve all properties (verbs) will go
up the ancestor chain until it finds a readable object with
properties (verbs) defined on it.
+thisonly Specifying . (:) to retrieve all properties (verbs) will only
display properties (verbs) defined on the object itself.