Use this field to specify additional variables across the meta-analysis that contain major allele identifiers.This field is used only when one or more of the data sets selected, after the first, uses a variable with another name for the Major Allele Variable. All variable names for the 2nd through the last data set must be specified here.
For example, to specify the additional major allele variables MajorAllele_1 and MajorAllele_2, type MajorAllele_1 MajorAllele_2 in the text box, as shown below: