sed is as specified in the Single UNIX Specification but with differences as listed below.
Certain aspects of internationalized regular expressions are optional; see Internationalization and Regular Expressions>.
The behaviors specified in this section are expected to disappear from a future version of the LSB; applications should only use the non-LSB-deprecated behaviors.
prints out the version of sed that is being run and a copyright notice, then exits.
is equivalent to -n.
is equivalent to -e.
is equivalent to -f.