DVD-10 means a two-sided DVD disc that hold single data layer on both sides.
Effectively this means that DVD-10 is a dual-sided DVD-5 and can hold 8.75 gigabytes of data with 4.38 gigabytes on each side. Two-sided discs need to be flipped over in order to access the other data side.
Unfortunately many blank DVD media advertisers mislead customers to believe that these discs are actually blank DVD-9 discs in hope that they could copy their dual-layer discs directly to blank discs.
Other regular DVD size acronyms are: