An excerpt:

"Although fans of the DVD+R format hate to hear this, the DVD+R format is a rogue format, invented by greedy companies that were unwilling to pay royalties to the DVD Forum in order to use and develop the DVD-R format and/or use the DVD logo. The DVD+R format does not carry the DVD logo because it is not an official DVD format."

See the whole page here:

[Link: digitalfaq.com]