Mike Stangel,
Would you also include suffixes like "d.e." and "d.y." These are an abbreviation of "den eldste" (the oldest) and "den yngste" (the youngest) in Norwegian. In Norway, these are common to use in family books and genealogy to differentiate between siblings with the same name. They were also (sometimes) used during the period when these people were still alive and not only in posterity. I have seen them being used in old church books.
It was common in Norwegian family history to give the next child in a group of siblings the same name as the previous one if it died before the next one was born. The same is true if a married couple had two parents with the same first name, then it was not uncommon that two of the children could get the same name. Naming traditions was strictly followed. Occasionally, the naming of grandparents with the same name was given to only one child, but sometimes the parents decided to "honor" both grandparents by naming two of the children after each of these, even though they had the same name. And many of these kids would also grow up. It is therefore easy to make mistakes of these and believe they are the same person even though they wasn't and had a separate life from each other as adults.
If the child mortality in a family was large, it was also common to have more than two children of the same name. For example, if the son "Olav" died as a an infant or small child, the next son would be called "Olav", but if this child died before the third son was born, this one would also be named "Olav" (for the third time). This way it continued to a higher number. I have seen several examples of this in genealogy. Therefore, in some cases, the suffixes "d.m." which is abbreviated to "den mellomste" (the middle [one]) should be used. If there are even more people with the same name, you must use "d.n.y." ("den nest yngste", the second youngest) and "d.n.e." ("den nest eldste", the second oldest).
Thus, the suffixes "d.e.", "d.n.e.", "d.m.","d.n.y." and "d.y." should be added to the system with "lower case", "period mark(s)" and "no space" between. As listed in order: the oldest, the second oldest, the middle, the second youngest, and the youngest. They are used in the same way as "Jr." and "Sr." is used in English-speaking countries to differentiate between father and son with the same name (or mother and daughter).