Since all private addresses start with FC0, doesn't that mean you could put the network ID in the first segment? So I could have 10 networks, FC00 - FC09. That makes addresses even shorter like FC01::1. Is that allowed?
IPv6 private addressing
In theory yes, you would end up with 10 separate networks with each network space having 2^112 number of host per network. Now, having said that, this would mean that you're willing to statically control those network spaces too.
This is probably overkill, but I want to add a little more to Ronnie's answer. The biggest risk you have with this is limiting yourself in the future. Here are some suggestions I would make to get easy to remember addresses, and future-proof yourself.
Don't use FC0x for your networks. The official private range is fc00::/7 just like you stated. However, in RFC4193 they require the 8th bit to be "1" to identify that the address is locally assigned. You can certainly ignore that requirement, but it would be safer to follow it. That means your address space would actually be fdxx::/8.
Don't use the first block for your networks. The address space is huge, but by using that first block you start applying limits. Granted, they are limits most people would never hit, but consider using the second block instead. For example, if you use:
You would have just over 250 networks. That's more than enough for small and medium businesses, but large and enterprise organizations can exceed that pretty easily. Instead, if we used:
fd00:0::/32 fd00:1::/32 ... fdff:fffe::/32 fdff:ffff::/32
We would end up with over 16 million networks. I can't think of a single company that would have a problem with that limit.
Applying that to your original example, you could certainly use FC01::1/7 as a nice short address, but consider using FD00:1::1/32 instead. It's two extra characters, but you will be future-proofed.
Thanks for watching,
Thank you both. This site is amazing.