Interchangeable Letter

When researching Mexican records, Mexican spelling of names was varied. "B" and "V" were interchangeable as well as "s" and "c". The "I" and "Y" were used in many names such as "Ines" or "Ynes", "Ynojosa" and 'Inojosa". The "ll" in the middle of a surname has the same sound as "I" or "Y", but I've never seen it spelled with those two letters.