Kill lines with a phrase. Select a text. Enter some phrase into the Famous text entry. Apply this function. As a result, all lines containing your phrase will be deleted from the selection.
Kill all lines except with a phrase. Select some text. Enter some phrase into the famous text entry. Apply this function. As a result, all lines without your phrase will be deleted from the selection.
Kill all lines < N characters - Kill in the selection all lines smaller than N (value in the Famous text entry) characters.
Kill all lines > N characters - Kill in the selection all lines smaller than N (value in the Famous text entry) characters.