[error all=1 hide=1 comment="Clear errors"] displays 1

The tag:

[error all=1 hide=1 comment="Clear errors"]

as found in checkout.html, seems to return a "1" if there were errors that
were cleared.  So a "1" gets displayed at the bottom of the page.

Is this by design?  Is there any way of stopping it returning, or at least,
displaying a "1"?

Thanks