FWIW:
With my several WDOC HPWORD documents are files of similar name with
FCODE=3332.

:L icc1@
THU, JUN 17, 1999,  6:14 PM

FILENAME  CODE  ------------LOGICAL RECORD-----------  ----SPACE----
                  SIZE  TYP        EOF      LIMIT R/B  SECTORS #X MX

ICC1      WDOC    256B  FA         222       1021   1      512  2 32
ICC1AFF   3332    256B  FA          16       4096   1      256  1  8
ICC1BFF   3332    256B  FA          16       4096   1      256  1  8
ICC1CFF   3332    256B  FA          16       4096   1      256  1  8
ICC1DFF   3332    256B  FA          16       4096   1      256  1  8
ICC1EFF   3332    256B  FA          16       4096   1      256  1  8
ICC1FFF   3332    256B  FA          16       4096   1      256  1  8
ICC1GFF   3332    256B  FA          16       4096   1      256  1  8
ICC1GXFF  3332    256B  FA          16       4096   1      256  1  8
ICC1HFF   3332    256B  FA          16       4096   1      256  1  8

There is a feature of HPWORD that allows included text, such that your
document can
include pages of other documents.  These 3332 files appear to be this
included data.
This is still THEORY.

Your WDOC file file have system variables of type $FF-filename like
$FF-ICC1AFF,
And $I-FLOW,2.
The $FF declares the file to include from -- a special btree type file --
where the $I
declares a key value of the text to include.
The HPWORD,WORDUTIL print and keep functions to not process these special
system variables. Nor do the WORD intrinsics. So I would suspect that the
printing
function of HPWORD did this feature.

+=====================================
 Keven Miller   KC7LYD  ICQ 5721825
 [log in to unmask]   (Salt Lake City, Utah, USA)
+=====================================