I ran across this Q&A while reading over the ATA 186 FAQ on Cisco's website:

Q. What if the telephone cord is too short to reach the nearest telephone?

A. Replace the six foot line cord with any RJ11 cord.

Although this may seem funny at first I think that the answer is technically wrong.  Here is how the conversation would go when the customer calls into TAC in regards to this issue:

TAC Engineer 1: Thanks for calling Cisco TAC.  How can I help you?

Customer: I have an ATA 186 and the six foot cord provided doesn't reach the phone.

TAC Engineer 1: Have you tried rebooting the ATA to see if that resolves the problem?

Customer: Yes and I've even tried to update the software load on the ATA but the six foot cord still won't reach.

TAC Engineer 1: I'm going to need to escalate this case.

TAC Engineer 2: Hello customer!  Let me review the ticket notes and see if I can find a solution.

Customer: Thanks!

TAC Engineer 2: The ATA 186 FAQ states that if the phone can not be reached using the six foot cord provided to replace it with any RJ11 cord.

Customer: Great, I have another RJ11 cord right here!

TAC Engineer 2: Let me know if this solves your problem.

Customer: No it didn't solve the problem.  The ATA still can't reach the phone.

TAC Engineer 2: So you replaced the RJ11 cord but you still can't reach the phone?

Customer: That's correct.  I replaced the six foot cord that came with the ATA with a three foot cord but it still doesn't reach.

TAC Engineer 2: D'OH!

So technically "any" doesn't really work.

I can remember having to deal with a couple real situations simular to this scenario ;)