Newbie question concerning strings

[ChrisRathman.6335977 at bloglines.com]

In the CTM book, an example is given on threads which prints to browser in
the form of:

   {Browse start}

Which in playing around seems to be equivalent
to:

   {Browse 'start'}

In playing around further, it appears that a
word is automatically assumed to be a string if it begins with a lower case
alpha character and has alphanumeric or _ in the remaining positions.

Was
wondering what the rules for parsing this as a string are for Mozart/Oz?

Thanks,
Chris Rathman