Here:
Zend Framework: Documentation .db.select.building.limit

And here:
Paging Data Sets With PEAR Pager EAR-Pager

It seems the two articles use different LIMIT clause syntax.
The manual is: LIMIT <limit>, [<skip>]
But the tutorial on Pager is:
LIMIT [<skip>,]<limit>

I am wondering, which is the correct one? or we can use both?