• Any name that starts with a letter can be used as a variable name.
  • For instance: v, v1, v1_1, v_filename_4

  • To add a string immediately after a variable name can be confusing.
  • The situation is solved by putting the variable name inside braces.

  • Examples:
    $ v=im1
    $ echo $v_new

    $ echo ${v}_new

  • NB: all unused variables are blank by default (generate no error)