PSPad recognize file by it's extension. Does you WinSCP keep PHP extension? PHP can be open as HTML, if in the program settings / HTML multihighlighter option Open PHP in multihighlighter is enabled Syntax isn't enabled automatically, depends of the file size. Check program settings / Direct edit button and variable HLUpToSize=nnn where nnn is number of bytes. Change value e.g. to 1 million
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