title: what's the meaning of samtools mpileup result "^F"
body: <p>this is a part of samtools mpileup result:</p>
  
  <pre><code>chr7    55241514        G       2786    .....................
  chr7    55241515        C       2786    .....................
  chr7    55241516        C       2786    .....................
  chr7    55241517        G       2786    .....................
  chr7    55241518        T       2786    .....................
  chr7    55241519        G       2786    .$.$.$.$.$.$.$.$.$.$.
  chr7    55241520        G       2776    .....................
  chr7    55241521        C       2776    .....................
  chr7    55241522        T       2776    .....................
  chr7    55241523        G       2774    .....................
  chr7    55241524        C       2774    .....................
  chr7    55241525        T       2774    .....................
  chr7    55241526        G       2723    .....................
  chr7    55241527        G       2723    .$.$.$.$.$.$.$.$.$.$.
  chr7    55241609        C       7999    ......^F.^F.^F.^F.^F.
  chr7    55241610        C       7999    .....................
  chr7    55241611        C       7999    .....................
  chr7    55241612        A       7999    .....................
  chr7    55241613        G       7999    .....................
  chr7    55241614        C       7999    .....................
  chr7    55241615        T       7999    .....................
  chr7    55241616        T       7999    .....................
  </code></pre>
  
  <p>I don't know the meaning of "^F", I have consulted the help of mpileup commander, a symbol ‘^’ marks the start of a read. The ASCII of the character following ‘^’ minus 33 gives the mapping quality. A symbol ‘$’ marks the end of a read segment. and it didn't say anything about "F", does anybody know what's meaning of "F" in this result.</p>