As the name implies, the parser directives instruct the Dockerfile parser to handle the content of Dockerfile as specified in the directives. The parser directives are optional and must be at the top of a Dockerfile. Currently, escape is the only supported directive.

We use the escape character to escape characters in a line or to extend a single line to multiple lines. On UNIX-like platforms,   is the escape character, whereas, on Windows, is a directory path separator and ` is the escape character. By default, the Dockerfile parser considers is the escape character and you could override this on Windows using the escape parser directive, as shown here:

# escape=`