OPE : OPE could be linked to other OPEs
This is actually done with the FILES but :
FILE module is optionnal,
a link could exist between OPEs without link to a FILE (this is common for old OPEs),
the link must be qualified (a type of link - non-hierarchical list), (i.e. : "Is linked to" (neutral link), "Is a part of", "administrative link",...)
an OPE could be linked to one or more OPEs,
a link between to OPEs must be displayed on both sheetfiles (with html-link), even if it has been define only from one of the OPEs.
Sometime DOCS and FINDS are only stored with reference of one OPE whereas there was many operations, reports etc... This is common for old operations, or not so old... Sometimes we have only one (the first one, the last one, ) PATRIARCHE reference for many OPEs...