The International Cessna^® 170 Association

Sorry about my ignorance, but in the states, when you send, for example, a magneto, to a certified repair station, when it is overhauled and go back to the owner, does it have any kind of documents that sez it was OH. If not, anyone can explain to me the term "yellow tagged". Saludos (ah, my generator didnt arrive yet, its a month grounded due some incompetent bussinesmen)

FEDE

Fede,
If a repair facility "Yellow Tags" an item, that means that they certify that the part is "Serviceable"
A yellow tag is a serviceable tag.
A green tag is a repairable tag.
A red tag is a condemned tag

If a repair facility "Yellow Tags" an item, that means that they certify that the part is "Serviceable"
A yellow tag is a serviceable tag.
A green tag is a repairable tag.
A red tag is a condemned tag

That is NOT True.
There is no where in the US FARs that mentions a Yellow Tag, it is a common method of telling the user that the item in their opinion is usable.
The A&P who installes the item declaires it airworthy.
The Repair station that overhauls an item must make out a work order, THAT is the requirement of the FARs and that is what authorizes the A&P to return it to service as overhauled.

Fede (and others)...
While Tom's reply is technically and literally correct,..it is splitting legal hairs as far as the real world is concerned.
The documentation that accompanies an overhauled or repaired and airworthy part is commonly referred to as a "yellow tag". This is in deference to an old military system which commonly used a yellow-colored tag to indicate a part that had been returned to an airworthy status and was "Approved" for return to service. (And, yes, it was the mechanic who determined that it was suitable for return to service, and as always it is the pilot who actually "returns" it to service when he fires it up, turns it on, or whatever.)
This "yellow-tag" system has been superceded in the U.S. by what is now referred to as a Form 8130, and the document, as always, could be any color whatsoever. It usually referred to a repair or work order in the text. Most of us still refer to the documentation that identifies an airworthy part as a "yellow tag", no matter the actual color of the paper. And, we also use the phrase "to yellow tag" as if it were verb, when what we really mean is that the part is to be repaired in accordance with approved methods and materials, for the purpose of being returned to an airworthy status eligible for installation. A "green tag" was formerly used to indicate an item that had been removed and was suitable for repair or re-build. A "red tag" was used to indicate an item that was incapable of being returned to service.
This is all remindful of the system of traffic lights in Japan after World War Two. Formerly they had two types of traffic lights. RED lights for STOP!, and Blue Lights for Proceed! After the U.S. military took over the practical administration of the system during the occupation, all the traffic lights were changed to a Red and Green system. Despite this fact, it is still common even today to sit at a traffic light and, ...missing the light change from Red to Green,...be prompted by a passenger in perfect and very polite Japanese....."Blue Light!" ....regardless of the actual color of the light.