Hello There, I have some questions about the eVouchers. I tried to look at the forum and at the FAQs and did not find the answers. Sorry if I ask something that had already benn asked in the forum.

1. Lets say I fly TLV-FRA-ORD one way (all operated by LH). Do I need 2 eVouchers for each flight (e.g. 4 vouchers) or only 2?
If only 2 - can I use the same amount of vouchers for TLV-FRA(LH)-ORD(UA)?
2. Can I use eVouchers on CO or US (according to the FAQs no, I just wanted to check again)?
3. Is there a list of booking classes on which I can use the eVouchers?

THX in advance.