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 2 nd 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: