```
gi|110640213|ref|NC_008253.1|_4832863_4833322_0:0:0_0:0:0_11    163     gi|110640213|ref|NC_008253.1|   4832863 23      70M     =       4833253 460     TACCGCAATGTGCTTATTGAAGATGACCAGGGAACGCATTTCCGGCTGGTTATCCGCAATGCCGGAGGGC  2222222222222222222222222222222222222222222222222222222222222222222222  XT:A:U  NM:i:0  SM:i:23 AM:i:0  X0:i:1  X1:i:1  XM:i:0  XO:i:0  XG:i:0  MD:Z:70 XA:Z:gi|110640213|ref|NC_008253.1|,+4019608,70M,1;
```

Suppose I have the following alignment (illustrated above). As you can see there are multiple alignments in the form (rname, pos, cigar, NM), where NM defines edit distance. I have noticed that the pos field can either be positive or negative. 

Where do positional values beginning with a positive or negative sign start in the sequence specified by rname?
Following the advice given from Brian Bushnell and Istvan Albert, I was able to find the block of code that produce the multiple hits. Under `bwa/bwase.c`, beginning at line 467, we can see that, in fact, the `+` and `-` signs refer to the positive and negative strands.