I had wondered when I first got the Nokia what the difference was on the cards and found this:

What's the difference between MMCmobile, RS-MMC & DV RS-MMC
Date: Thursday 15 December, 2005

Author:

The 3 card formats, MMCMobile, RS-MMC & DV RS-MMC are so alike there is often confusion about the differences between them. We hope the following facts help to clear up your doubts about the differences between these cards.

Article Content:

The Main Differences are as Follows


DV RS-MMC is the same as a standard RS-MMC, but with dual voltage capability.

MMC Mobile has 13 contact pins rather than 7 used in RS-MMC and DV RS-MMC.

MMC Mobile has been designed for the latest generation of mobile phones and is manufactured according to the new MMC4.1 spec, allowing it to reach a potential maximum of up to 52MB/s. Great for high megapixel camera phones!

Dual Voltage RS-MMC and RS-MMC are only capable of 2.5MB/s transfer rate.


MMCplus™ and MMC Mobile™ Cards, based on the latest MMC System Specification Version 4.0, are the most advanced memory cards available today, offering the highest transfer speeds (up to 52MB/sec, or 416 Mbits/sec), and the greatest flexibility, including support for dual-voltage operation (1.8 and 3/3.3V), and multiple bus widths (x1, x4 and x8 bit).While the new cards have 13 pins to accommodate the additional features, they are backwards compatible with previous version MMCs (7-pins), thus bridging the mobile storage applications of yesterday, today and tomorrow.