Does anyone know what the capital 'I' might represent in this date? There is no French month that begins with 'I', and the document uses numbers for months as well as spelled out month names interchangeably. I've found every month written somewhere in the document, so I couldn't figure it out by process of elimination. The document is a pedigree chart prepared by a genealogist at the Fribourg Archives in Fribourg, Switzerland in 1936, and there are many dates where this 'I' represents a month. The pedigree chart's information seems to be derived from church records, if that's a clue.
I'm baffled! Any guesses?