Yep, got my head screwed around the wrong way this morning...the 'voyage report' fulfils the requirements of the journey log, more relevant to this question.
JAR-OPS 1.1055 Journey log
(a) An operator shall retain the following information for each flight in the form of a Journey Log:
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(3) Name(s) of crew member(s);
(4) Duty assignment of crew member(s);
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...and we don't put anyone's name on the Operational Flight Plan (other than the Captain's actually) because they are detailed on the Journey Log as per:
JAR-OPS 1.1060 Operational flight plan
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(b) Items which are readily available in other documentation or from another acceptable source or are irrelevant to the type of operation may be omitted from the operational flight plan.
<snip>