A-code significant entities

### Game-level entities significant for the A-code kernel 12.73. #### Conventions "Automatic" means that the entity is declared automatically. Automatic entities may be explicitly declared by the program, but if so, must be of the correct type. If an entity of that name is declared as some other type, this is treated as a compilation/translation error. "Optional" means that the entity may but need not be declared by the program. An entity of that name but of a different type is treated as a compilation/translation werror. #### Variables
       STATUS - automatic variable
          Use: 1. Set by the kernel to indicate the number of words
                  in the player's command being processed.
               2. Can be set by the program to various values in
                  order to pass information to the kernel.
          Flags:
             MOVED - optional flag
                Use: Set by the kernel if player has changed location
                     Cleared by the kernel otherwise
             JUGGLED - optional flag
                Use: Set by the kernel if player's inventiry has changed
                     Cleared by the kernel otherwise
             PLS.CLARIFY - optional flag
                Use: Cleared by the kernel
                     Set by the program in order to trigger orphan processing
                     on next player input.
          States:
             BADSYNTAX - automatic state
                Use: Set by the kernel if the current player command cannot
                     be parsed.
             NO.MATCH - automatic state
                Use: Set by the program to indicate that no abbreviation or
                     approximate matching is to be performed on the next
                     player command.
             NO.AMATCH - automatic state
                Use: Set by the program to indicate that no approximate
                     matching is to be performed on the next player command.
             -1
                Use: Set by the kernel to signal game restore on start-up.

       HERE - automatic variable
          Use: Set by the kernel to the refno of the player's last location.

       THERE  - automatic variable
          Use: Set by the kernel to the original player's location when
               relocating the player

       ARG1 - automatic variable
          Use: Set by the kernel to the refno of the player's verb
          States:
             BADWORD - automatic state
                Use: Set by the kernel if the player's word cannot be understood
             AMBIGWORD - automatic state
                Use: Set by the kernel if the player's word can be an
                     abbreviation of more than one vocabulary word
             AMBIGTYPO - automatic state
                Use:Set by the kernel if the player's word can be matched as a
                    typo in more than one way
             SCENEWORD - automatic state
                Use: Set by the kernel if the player's word is not found in the
                     vocabulary but matches a word (in excess of three characters)
                     in a latest location description or in a text displayed
                     since the last move.

       ARG2 - automatic variable
          Use: Set by the kernel to the refno of the player's noun
          States: (as ARG1)

       ARG3 - automatic variable
          Use: At present used solely for EXCEPT processing. If player's
               command is of the form  ALL EXCEPT , ARG3 may
               be set by the kernel to BADWORD, AMBIGWORD or AMBIGTYPO,
               if appropriate.

       CONTEXT - optional variable
          Use: Solely for CGI-mode operation
          Value: If non-zero, indicates the current command to be
                 a response to a query, the value (as set by the program)
                 indicating the nature of the query.
          Flags:
             PROMPTED - automatic flag
             Use: Set by the kernel if the player has been prompted.

       UNDO.STATUS - optional variable
          Use: undo/redo processing
          UNDO.OFF - automatic flag
             Use: If set, indicates undo/redo commands being inactive
          UNDO.INFO - automatic flag
             Use: Set if undo off by default, permanently unset if
                  undo switched on by the program
          UNDO.NONE - automatic flag
             Use: Set if undo/redo is forbidden by the game
          UNDO.TRIM - automatic flag
             Use: Set by the kernel if the level of undo/redo was found
                  to be excessive and had to be trimmed to match the
                  existing undo histiry
          UNDO.INV - automatic flag
             Use: Set by the kernel if the player's inventory has changed
                  as the result of undo/redo.
          UNDO.BAD - automatic flag
             Use: Set by the kernel if undo/redo not possible.

       DWARVEN - optional variable
          Use: If set to non-zero, all text output by the game is shifted
               circularly one position up in the alphabet and all player
               input is shifted one position down.
               If set to zero, any portion of game text delimited by %
               signs is output shifted one position up.

       ENTNAME - optional variable
          Use: if pointing to an antity, this is expanded in texts as the
               actual 'primary' name of the entity in question.

       PROMPT - reserved optional variable
          Use: none at present. Reserved for specifying non-standard prompt.
#### Objects
       ALL, EVERYTHING - optional object
       IT - optional object
          Use: Set by the kernel as a part of default processing (the
               DEFAULT minor directive) if a suitable default is identified.
#### Object flags
       SCHIZOID - automatic flag
          Use: objects so flagged are deemed by the kernel to be present
               in their ciurrent location as well as in the one with the
               refno one higher than that of the current location.
#### Places
       INHAND - automatic place
          Use: the location of objects deemed to be in player's hands.
#### Place flags
       BEEN.HERE - automatic flag
          Use: Set automatically by the kernel when moving the player to
               this location.
#### Texts
       TYPO - optional text
#### Optional words
       FIRST.SPECIAL - optional marker verb, should use flags instead
       LAST.SPECIAL - optional marker verb, should use flags instead
          Use: These pseudo-verbs delimit the list of verbs for which
             objects are not to be checked against the vocabulary
             (e.g. verbs such as SAVE, RESTORE, SAY...)

       AGAIN - optional verb
          Use: If given on its own, repeats the previous (possibly compound)
               command. If embedded in a compound command, repeats the
               preceding simple command within the compound one (NB: it
               is a repeat, not a reset to the previous simple command --
               that would be a loop!)

       EXCEPT, BUT - optional word
          Use: In commands triggering the DOALL loop, specifies the
               signals the rest of the simple command to be a list of
               objects (comma and/or space separated) to be exempted.

       UNDO - optional verb
          Use: The UNDO player command. Its presence causes UNDO.STATUS
               to be declared, unless already declared by the program.
               (NB: does not force the REDO verb!)

       REDO - optional verb
          Use: The UNDO player command. Its presence causes UNDO and UNDO.STATUS
               to be declared, unless already declared by the program.

       SAY - optional verb
          Use: Used by the kernel to format a special text buffer for the
               special action pre-say (EXEC 27)

       DEFINE - reserved optional verb
       UNDEFINE - reserved reserved verb
          Use: None at present. Reserved for player defining his own command
               abbreviations.