I was working on the Multiple Sheets file for for the Calc guide and the outline discusses hyperlinks and URLs in Calc.
I am not sure what to say about those in the chapter. Just that you can make them, or is there more to it that someone can think of?
Are there any "gotchas" or limitations that people should know about? For example, the text that a hyperlink displays will not change if the thing linked to changes. That's why, in Writer, it's usually better to use a cross-reference if possible, instead of a hyperlink. AFAIK, Calc doesn't have x-refs in the same sense that Writer does, but there might be something in Calc that does some jobs better than hyperlinks, but which people might use hyperlinks for.
Cheers, Jean (writing to you during lunch break at the OOo MiniConf in Canberra, Australia)
