4th edition question about magic items

Got a question about crafting magic items. When designing the effect (spell in essence) of a item do the magi learn that spell at the same time (if the item is made of course)?

Or can that spell be learned from the lab notes in a similar way that you would learn a spell from a text?

Or can only a magi make a object with a spell they already know (a requirement of sort)?

I don't believe that a magus creating a magic item automatically learns the spell that mimics the effect he is instilling.
If a maga already knows a spell she wishes to enchant into an item, we have been allowing a bonus to the lab total equal to the magnitude of the spell. (Like the bonuses for similar spells on pg 69 of ArM4) But this may be a house rule, as I am not finding this in the Lab Work chapter.

It sounds like a house rule. Or at least I, like you, have not found fount that either. =)

But it sounds like a "normal" thing keeping it in like with the spirit of the game.

Similarly that is what I was thinking with being able to learn the spell from the lab notes. Making the labenotes more useful, as they are now they are only of use for reproducing a exactly similar item. Which is kind of a narrow use.