This is an extension to issue 245262 about Extend in Less.

Example less code:

.badge {
  display: inline-block;
  &:after {  /* Prefix notation is supported since issue 245262 */
    display: none;
  }

  a& {  /* Unexpected token LESS_AND found */
    &:hover,
    &:focus {
      text-decoration: none;
    }
  } /* Unexpected token RBRACE found */
}

/*Resulting CSS. See http://less2css.org/

.badge {
  display: inline-block;
}

.badge:after {
  display: none;
}

a.badge:hover,
a.badge:focus {
  text-decoration: none;
}
*/