TOPIC:

DMcL
Here is his official record from the reprint of Services of British Officers from the period 1899-1902.

D-A-A-G indicates he held the rank of Deputy Assistant Adjudant General. The meaning of that is a good one for you to look up!
In posting the extract from the DSO book, I was quite aware of the error in the commission date. Unfortunately, it is rather difficult to correct a work published long ago. Indeed, modern scanning of texts from long ago sometimes throws up errors in dates and spelling - I have had examples of this in my own research and in proof reading for the "Army Mentions" elsewhere on this site.
You can always create a post on this site under a suitable heading for your distant relative; which corrects the entry in the DSO publication - along with additions to his career you may run across. I would encourage you to do this.
Regards
IL.

Naval & Military Record and Royal Dockyards Gazette 31 March 1915:



And when he was a Lieutenant: