Decipher the Garmin Update Codes...?

 

I often receive emails from Garmin with update notices and what I believe are specific references to the eligible devices, e.g., GPSMAP 695/696 6.60 (April 11, 2013).

What does that mean; is there a way to crack the code?

My device is older (nuvi 260w), however, I do keep the maps up to date. I don't really expect a lot of updates, but I'd like to know what the emails refer to when I do receive them.

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RBF