How does commnad tail implement

Applications Programming
1

How does commnad tail implement ?
Thank you .

2

Captured from Man Page:

   tail  accepts  two  option  formats: the new one, in which
   numbers are arguments to the option letters, and  the  old
   one, in which a \`\+' or \`-' and optional number precede any
   option letters.

   If a number \(\`N'\) starts with a \`\+', tail begins  printing
   with  the Nth item from the start of each file, instead of
   from the end.

for more info you can check your man page. Might be diffrent from mine.