In other words TopStyle fired a page invisible to browsers and Search Engines that I considered "safe".

Fortunately I have a "checking robot" that detected the problem and sent me an email alert.

(There may be a feature that already does what follows.  I didn't find it.  If it's there my apologies in advance.)

It seems to me that TopStyle acts like a robot, but with privileged access:  it can see the filing system.  The web site in question has a robots.txt which prohibits access to the files I don't want touched.

To guard against such problems l suggest:

1. TopStyle reads the robots.txt file and, by default, adhere to it instructions.  (When using server mappings to access pages.)
2. TopStyle should be individually addressable as a user agent in robots.txt.

(There are possible applications of the robots meta tag, for a similar purpose.  My current concern cannot be addressed that way.  Sitemaps are not a mechanism for doing this as they only list pages you can access.)

I'm usually careful about this sort of thing but let my guard down when testing!!

I'll keep Topstyle away from web sites that have this issue until it's sorted.