Exceptions are ok for special cases. Try to orient the figure for easy viewing. This is to ensure that documents are not moved, changed, etc. rendering the ilog pointer useless. The Operations log is intended to carry operator information, responsible persons, alarm conditions, changes in state of the site, the site physical installation, vacuum system, the data acquisition system. Changes in the detector installation should go in the detector log, along with all measurements and analysis.
Examples are the development of procedures, or measurements of resonances of suspended optics.
In this case the DCC number should be added to the original entry as a comment to lead the reader to a definitive document. An ilog entry might just indicate that the data have been incorporated in a new revision of an existing document, and point the reader there. It is best if associated information lies together, and so if e.g., some spectra of measurements are made on the day following the experiment, it is best to put them in the log on the actual day of the experiment. An alternative, when there is evolution in the interpretation, is to put a comment in referring to the later analysis. A search for 'boot' finds 'boot', 'reboot', 'booted', 're-boot', etc.