FWIW I have filled out lots of From 1120S (subchapter S or closely held corporations, usually family-owned) and From 1065 (partnership) returns over the years. Percentage of ownership for each individual taxpayer is disclosed to make allocations for each taxpayer's K-1 so they can use this data for fill out their Form 1040, with primary data going into their Schedule E. I guess percentages work as well as percentage of shares or shares, but we were a subchapter C corporation and percentages are not computed to report this data to the IRS or Federal Government. Stay well. AJ