Valid sheet name characters

[Kohei Yoshida <kyoshida@novell.com>]

Hi folks,

This discussion came up while working on allowing more special
characters in a sheet name in Calc, and Eike recommended that I bring
this up to this list for further discussion.[1]

Here is the story.  Currently, quite a few special characters are
prohibited in Calc's sheet name, and that causes a problem for
interoperability with Excel as Excel allowed more special characters
than Calc does.

Initially, we were planning to allow all special characters to be used
in a sheet name, to entirely lift the character restriction as a whole.
I investigated a little, and found out that Excel, while more lenient
than Calc at present, still disallows all of : \ / ? * [ ] characters.
Also, a single quote character is not allowed at the first or last
character position.

So I proposed that we at least place the same restriction as Excel to
avoid surprises, since Excel can't deal with sheet names that are not
valid Excel sheet names (Excel converts such sheet name to 'repaired' or
something, I forget).

The ODF spec, however, doesn't mention anything about disallowed
characters in the table:name attribute, which implies that all
characters are allowed in table:name.

The question is, what should we do?  My personal point of view is that
we should at least mention Excel's restriction on sheet names, and
probably leave the decision down to the application.  Another
possibility is to make that an official restriction in the spec, or just
leave it as is with no restriction (and tell Excel to fix it up).

Any thoughts?

Kohei

[1] http://www.openoffice.org/issues/show_bug.cgi?id=6087

-- 
Kohei Yoshida - OpenOffice.org Engineer - Novell, Inc.
<kyoshida@novell.com>