sets the preserve carriage returns flag. When a file is loaded into a buffer for which this flag is false, both CR (carriage return) and NL (new line) characters are treated as line terminators. If the flag is true, CR characters do not act as line terminators but are instead preserved in the buffer. This flag has no effect except when loading a file into a buffer.
If you invoke
PreserveCR with no arguments, it will toggle the flag.
If you specify 0 or 1, the flag will be set to false or true,
respectively. An upper case ‘P’ will appear on the status bar if the
flag is true.