Question about Annotating SNPs

Hi - I’m very new to using Hail so apologies if this has been asked before, but I am trying to annotate roughly 12 million variants with their RSIDs and have 2 questions:

  1. I have columns for chrom, pos, ref, and alt alleles; however, some of the ref alleles are missing or have indels instead (e.g. ins:me:Alu). Is there a way to annotate just based on chrom and position only?
  2. About half of the SNPs aren’t being annotated even know there is no missing info. for example 1:758085:T:C does not get annotated but exists on ncbi