Good grief guys. This has never been true for SolidWorks files. There used to be a numerical code buried in the file (not in the header) that you could use to look up which version the file was saved in. You could also find readable text strings such as all the custom properties and their names, feature names, etc... Now (since like 2015 or so), the content of SW files is compressed/encrypted such that there is zero content readable in a text editor.