Opens a menu containing all permissible field names, and
lets you choose any number of them for editing. The permissible fields are
those defined in the configuration file (the supplied configuration file
defines all fields defined in the standard BibTEX styles, plus the fields
``keywords'' and ``abstract''). The fields are separated into Required,
Optional and Ignored fields, according to the entry type. The Required and
Optional fields for each entry type are defined in the configuration file
(see below), while the Ignored fields are all the rest. A check mark
(√) appears next to the names of fields which are not empty in the
entry being edited. Choose the fields using the arrows and space keys, or the
mouse. Clicking on a field name, or pressing `space' while the blinking
cursor is positioned on one, toggles the `chosen' status of that field. You
can also choose all the Required fields by clicking on ``Required'' or
pressing `R' from the keyboard. The Optional fields can also be marked in the
same manner. Exit the menu and accept the choices made by pressing
<ENTER> or clicking on `[ok]'. Pressing `ESC', or clicking on the Window
Close block, aborts the menu. Finally, all the marks may be removed by
clicking on `[erase]' or pressing `E'. The fields chosen are remembered for
next time, on an entry type basis.