> 'a,'b Between mark `a' and `b' > g/fred If the line contains the pattern Fred, execute the following command (s/dick/joe/igc) > s/dick/joe/ Replace dick

> 'a,'b Between mark `a' and `b' > g/fred If the line contains the pattern Fred, execute the following command (s/dick/joe/igc) > s/dick/joe/ Replace dick with joe > /igc i: Case insensitive g: Replace multiple occurrences on the same line c: Ask for confirmation on each substitution I may be wrong about some detail, but I believe that's it.