Yes, i can see the conflict of info in Type3 & 4 there. Beats me which one is right.

I don't have a Garminfone but i think the file structure is the same as the Nuvi 1xxx/2xxx/3xxx series. Your A50 certainly supports JCV and i think you could use either Type3 or 4 depending on screen resolution. The 1200 has lower screen resoultion so i guess the Type3 JCV is just lower res than that in Type4, maybe? However, if your A50 also supports ASR you may need to get Type5 to get ASR files. Type1 would have 3D building files which i doubt the A50 supports.

Have a look at the Garmin SG site to compare what features different Nuvis support and how they compare to your A50 features:
Code:
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If this doesn't help you, post again and maybe someone with an A50 can help you more. Like i said, i don't have access to an A50 so i'm guessing a bit with the above.