DVD+R: A recordable DVD format similar to CD-R in that it is a write-once medium. Backed by Sony, Philips, Yamaha, HP, and others.
DVD-R: A recordable DVD format similar to CD-R in that it is a write-once medium. Backed by Pioneer, Panasonic, Toshiba, and others.
Source:
http://www.hometheatermag.com/glossary/
In other words.. some companies use DVD+R and others use DVD-R.
DVD-R seems to be the better of the two.
Hope that helps.
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