Where does the Douglas sept of 'Douglass' originate

[Daryl John Douglass]

For many years as a youngster, we were told that there was a tradition of adding or subtracting letters from a name when a child was born 'on the wrong side of the blanket'. I have yet to discover the significance of the second 'S' in my surname. can anyone help me. Perhaps there is a reason that even  with all the Douglas DNA  that is registered on file, to date, I have not even been close to a match.

[Mark Stephen Elliott]

One can just began to imagine how may variation so name spellings I found for my name Elliott.

https://books.google.com/books?id=DuU9AQAAMAAJ&pg=PA197&dq=...

If you find the names Irwin, or Johnston, spelled as such the are likely from Ulster. In Ulster muster c1630 my name is spelled Ellot, and in 1650 colonies with English spellers which wanted to stick and "i", in a 1692 testimony is spelled "Elot", The early spelling on arrival to the American Colony can determine where the name most likely migrated from in the UK.

http://www.therjhuntercollection.com/resources/muster-rolls-c-1630/... Try Douglas and Doulgass

[Judith Fleenor]

I appreciated a previous posters condensing reasons down to the following:

It seems the prevailing theories for the second s of Douglass are

1) Clerical (3rd party) errors

2) Illiteracy errors (self errors)

3) Disambiguation between clans (Black and Red)

4) Something else.

I'd like to add to the something else for modern times.  The advent of computers and databases for genealogical research.  While I feel #3 above may have had real family/clan significance, because I know having two "s"es was of importance in my family.  Many documents may have not had the two "s"es because of #1 or #2 above.  Now in modern times to make things easier to search many databases have "normalized" spelling of names.  So what was Douglass, in the database becomes Douglas, or in another family name of mine what was Smyth, has become Smith.  So while the original spelling of the name may be of importance to the family, the computer doesn't care about the significance, it is optimized for searching.