The assignment of Case Numbers has I understand always proved to be frustratingly difficult owing to the loss of so much of the original documentation including it seems the Master List of Case Numbers.- No longer. Initially thanks to a THS booklet: The Titanic Relief Fund, which seems to be a copy of the Mansion House Titanic Relief Fund booklet dated March 1913, it is possible [in a number of cases with some added information from the Crew biographies on this web-site] to assign numbers to over 480 of the 673 [the Postal Workers are counted separately and Lazar Sartori was not accepted until August 1915] deceased Crew.
It became clear that the names were in three generally alpha-numerical groups: Deck Crew [numbers 1 to 23], Engine Crew [numbers 24 to 277] and Victualling Crew [numbers 278 to 673, plus number 679]. However, within each alpha letter the names were random. Such a List has long been known. The Crew List as published in US Senate Report 806. After allowing for one minor number adjustment, and three names [one failed-to-sail, one survived and one listed twice], all that is required is to place numbers 1 to 673, [with special notes for two numbers] alongside the names within the three Crew groups; in the exact order in which they are listed. - In all [except for the 3 erroneous duplicated numbers] 500+ cases where I either already had a Relief Fund number or say two numbers and two Crew with the same surname [but no way of knowing which number went with which name] when the numbers were applied to the names as they appear in Report 806 there is an exact numerical match with the numbers as given in the Relief Fund booklet.
87 numbers in the 1 to 673 bracket do not feature in the THS booklet reproduction. 16 of the 22 bandsmen, Harland & Wolff Guarantee Group and Postal Workers [plus steward James McMullin C.679] have numbers between 674 and 706, which is the highest number given in the THS booklet.