In dfedit big menu you will find a button ChildMenu which, when applied to a term, will generate a menu of insertion buttons for all the display schema variables in the term. For example, applying it to <x>.<b> will generate

#COVER # <x:[prompt]>
<b:[prompt]: * |Other> # <x>.<b>

You can then use these insert buttons to copy the child format commands into the format part of the display spec. When you're finished, just locate the point on the "cover" and delete with `(c-d)'.

This little menu is also generated if you use the `adj' command on an obref to create the model.

In dfedit big menu you will also find a button DFchild which will insert

<[?]:[prompt]: * |Other>.

You may then simply enter the strings, then select from the choices given for parenthesis control. (This is a generic method for offering choices, described in doc for edit choice.) Selecting Other will give you some more choices; see doc for parentheses for how to decide what you want.
If you want to change this slot, you can reinsert the choices with the * |Other button in DisplayForm EditMenu.
You can also use `(backspace)' to cycle through * (self) (<self).

You can also insert <[?]:[prompt]: * |Other> in the formats area with the `(c-<)' command

doc for display form dfchild

About: IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html