From the link you provided for 1910 instructions -
Number of farm schedule.—This question applies only to farm homes. If the home is a farm home, enter in this column simply the number of the agricultural schedule filled out for this farm. Make this entry opposite the name of the member of the family operating the farm.
Whether a survivor of the Union or Confederate Army or Navy.—This question should be asked as to all males over 50 years of age who were born in the United States and all foreign born males who immigrated to this country before 1865. Write ‘‘UA’’ if a survivor of the Union Army; ‘‘UN’’ if a survivor of the Union Navy; ‘‘CA’’ if a survivor of the Confederate Army; and ‘‘CN’’ if a survivor of the Confederate Navy. For all other persons leave the column blank.
Whether blind (both eyes).—If a person is either totally or partially blind, in both eyes, so as not to be able to read even with the help of glasses, write ‘‘Bl.’’ For all other persons leave the column blank.
Whether deaf and dumb.—If a person is both deaf and dumb, write ‘‘DD.’’ For all other persons leave the column blank. Persons who are deaf but not dumb, or persons who are dumb but not deaf, are not to be reported.
