questions on *date and *export

[Thomas Holder]

>> Why is it necessary to export points? Is there any disadvantage in 
>> using "*infer exports on"?
> 
> The advantage of using exports is that you can avoid a certain class
> of mistakes [...] the export concept was added to make connections
> explicit at both ends.

Thanks for your replys, Wookey and Mark. Then *export is just for
keeping a proper style.

Do you also know if multiple *date commands in the same *begin/*end
block (and not only in the beginning but in between the data) will be
valid with future survex versions, although the manuals says something else?

Thomas