HP DDL D40 Reference Manual page 208

SPI Tokens
If a bit filler or group of contiguous bit fillers is less than a byte long and is
contained within one of the two bytes of a word, the filler or group of fillers
assumes the same version number as all other bit fields in the containing byte.
If a bit filler or group of contiguous bit fillers is a byte long or longer and fills
either the upper or lower byte of a word, the filler or group of fillers is a
NOVERSION field. The remaining part of the bit filler or fillers, if any, assumes
the same version number as all other bit fields in the byte that contains the
remaining part.
If a bit filler extends across two bytes of the same word but does not fill up
either byte, the part of the bit filler on either side of the byte boundary assumes
the same version number as all other bit fields in the byte that contains the
filler.
DDL allocates words for bit fields according to the following rules:
A bit field inside a group structure that follows a nonbit field item starts on a
new 16-bit word. If you specify bit fields consecutively inside the group
structure, DDL allocates the same 16-bit word for all contiguous bit fields that
can fit in the word. For the next bit field that cannot fit in the same 16-bit word,
DDL allocates the next word.
Consecutive bit fields that occupy the same word have the same byte offset
value but different bit offset values in their records in the DICTOBL file. An
elementary item of another data type that follows a bit field item starts on the
next word.
A substructure containing only bit fields always starts and ends on a word
boundary, padded with implicit bit fillers when necessary. Such a substructure
is always an even number of bytes long, which conforms to how the C, Pascal,
pTAL, and TAL compilers allocate space for structures containing bit maps.
Token-Map Source-Code Output. The following guidelines apply to generating host-
language source code from token-map definitions:
If you request C, COBOL, Pascal, pTAL, TACL, or TAL source-code output, DDL
generates compatible data structures for the token map for the requested
language. The SPI routines use these data structures to construct and access the
specified extensible structured token.
DDL replaces any hyphen in the DDL map name with a circumflex (^) in a pTAL,
TAL, or TACL map name, and an underscore (_) in a C or Pascal map name.
Data Definition Language (DDL) Reference Manual—426798-002
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TOKEN-MAP Statement