Yes I too am interested in finding a method of 'coding' ancestors. I have put my Ancestry 'list of people' into an Excel file and would like to give a code to each person so I could tell that e.g. 'Jane Smith' is the wife of my third cousin once removed! Please could you give us an example of your code system?
Let's take the example you suggest - the wife of your third cousin once removed. There are two possibilities. The common ancestor you share with your third cousin would be your great-great-grandparent, with an Ahnentafel no. in the range 16 to 31 - let's take it up the male line to keep it simple, and say no. 16. His children will be 8, your great-grandfather, and 8+1, his younger brother, your great-great-uncle. The next generation will be 4, your grandfather, and 8+1.1, your grandfather's first cousin; the next generation will be 2, your father, and 8+1.1.1, your father's second cousin; and the next generation will be 1, yourself, and 8+1.1.1.1, your third cousin. Your third cousin once removed will be your third cousin's son, i.e. 8+1.1.1.1.1 and to indicate his wife, I would add an 's' for spouse, thus: 8+1.1.1.1.1s -- and if the lady in question were his second wife, the 's' (for the first spouse) would give way to 't', and so on.
The system can be extended to include her relatives, too. So, if she had been married before, her earlier spouse would be 8.1.1.1.1.1sr ; any children of her earlier marriage would be 8.1.1.1.1.1s.1 , 8.1.1.1.1.1s.2 and so on; her parents would be 8.1.1.1.1.1s/2 and 8.1.1.1.1.1s/3 ; you might also want to record her extended family, so her aunts or uncles would be 8.1.1.1.1.1s/2+1 or 8.1.1.1.1.1s/3-2 etc. The / indicates the start of a separate sequence of Ahnentafel numbers, now relative to her, instead of to the original sequence, relative to you. It will be apparent, therefore, that the incidence of either a letter or the slash will indicate that an individual so labelled will not be your blood relative
If the descent were through your great grandfather's elder sibling, the + would change to -, and if there were intervening siblings, then these would count either way from your direct ancestor, so that complete family might be: 8-4, 8-3, 8-2, 8-1, 8, 8+1, 8+2 . In these examples, the .1.1.1 etc indicate the first child in each case, irrespective of gender; if the descent is through younger children, the 1 would change to 2, 3 or higher numbers accordingly.
But your third cousin once removed could also be your father's third cousin, with the common ancestor a generation further back, which would mean that his wife's Ahnentafel-plus reference would work out to be 16+1.1.1.1s