[Tails-ux] Resuming web assistant after reboot

Instead of asking people to write down long url, open page on other device or print it I prepose following:

Let’s remember all user choices in WA as a binary number.
Example based on router-sajolida-20150325.odp:

1) OS select.
"Windows" choice encoded as "00"
"Mac" is "01",
"Debian/Ubuntu" is "10"
"Other" is "11".

User choses "Mac", we store "01"

2) Dest. media
"USB" is "0"
"DVD" is "1"

User choses "USB", we add "0" to "01" and get "010"

3) Install from scratch, code "1", user number is "0101"
4) Don’t have a CD burner, code "1", user number is "01011"

We arrive at the reboot point, and show following message:

You need to reboot and ….
After you rebooted you should open web assistant and enter the number "11" (that’s "01011" converted into decimal) to continue from where you left off. Please write this number down.

After user enters "11" we can parse it to get original choices.


Upsides:
Very easy for user.
We can collect this numbers at the end of assistant for full statistics if it won't cause privacy issues.
We know every user choice at every stage, no need to maintain lots of identical pages with substitutions for media type/OS/etc. We can just create a template for a page and generate versions for all the different OS's/media types/etc. For this optimisations we need to have full understanding of
Downsides:
Every change in hierarchy will throw off this number to an unexpected page. If this will be implemented as offline documentation this can cause trouble. We could perhaps have version of assistant in number ("1-11"), but this complicates things. Perhaps Q/A hierarchy should be done right for the first time, so we will update only articles without changing hierarchy?
Not that many possible values for reasonable length of code (13 bits for 4 dec digits). DK if this is enough.
Concerning statistics and privacy: if the adversary will benefit from such statistics and he has a capabilities of stealing internal system data then it's trivial for him to get same info by counting hits on various pages of wiki. But why we need this stats?