====== HapMap format ======
  * The header of Hapmap format files looks like: ''rs#SNPalleleschromposstrand genome_build centerprotLSID assayLSIDpanelLSIDQC_code'' followed by a list of sample identifiers.

  * a sample line of the hapmap format genotype file: <code>
rs169757 A/C Chr21 9928594 + ncbi_b35.1 broad urn:LSID:affymetrix.hapmap.org:Protocol:genotype_protocol_1:1 urn:LSID:affymetrix.hapmap.org:Assay:1612756:1 urn:lsid:dcc.hapmap.org:Panel:CEPH-30-trios:1 QC+ AC AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AC AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AC AA AC AA AA AA AA AA AA AA AA AC AA AA AC AC AA AA AA AA AA AA AA AA
</code>

  * The table describes the valid values for each column:

^ Column header ^ Description ^
| rs# | A string of characters starting with letters 'rs' then followed by digits, e.g. rs12345 |
| SNPalleles | All possible alleles (A, G, C or T) for the SNP with each separated by a forward slash, e.g. A/G |
| Chromo | Three-letter String 'Chr' followed by a number from 1 to 22 or a letter X or Y for sex chromosome, e.g. Chr22 |
| Pos | position of the SNP, an integer number |
| Strand | One single character, either '+' or '-'. '+' refers to a strand going from 5-prime telomere to 3-prime telomere, and'-' refers to a strand going from 3-prime telomere to 5-prime telomere. |
| genome_build | A string of characters, e.g.ncbi_b35.1 |
| Center | A string of characters,e.g. broad |
| protLSID | A string of characters, e.g. urn:LSID:affymetrix.hapmap.org:Protocol:genotype_protocol_1:1 |
| assayLSID | A string of characters, e.g. urn:lsid:affymetrix.hapmap.org:Assay:1612756:1 |
| panelLSID | A string of characters, e.g. urn:lsid:dcc.hapmap.org:Panel:CEPH-30-trios:1 |
| QC_code | Either 'QC+' or 'QC-' |
| genotypes | A pair of letters, with each letter chosen from the set of (A,G,C,T,N), e.g. AG |

\\
  * Note that all columns are case-sensitive if not mentioned otherwise, no space is allowed within each column