– Jeff Atwood
Although the second statement is true for almost all Windows applications; the first statement is NOT always true, especially for Microsoft Office products (Word, Outlook) even Windows text box dialogs.
You can test this by using the above examples in a Word document, Outlook email, text box, etc.; searching for one individual token of the entire expression, e.g. “word”. In these applications, the search will find “word” in both of the hyphenated AND underscored versions of the expression.
Also, you can Ctrl-Left-Arrow/Ctrl-Right-Arrow to the first last character of each token in both versions. Whereas applications that treat the underscored version as a single “word”, Ctrl-Left-Arrow/Ctrl-Right-Arrow will advance only to the first last character of the entire expression.