Let $f$ = $\{f_k\}$ be a pseudorandom function family.
  
  Let $G(x)$ be a pseudo-random generator such that:
  $G(x) = f_x(0^k)f_x(1^k)$ where $k=|x|$.


I don't understand the meaning of $1^n$  and $0^n$, and the differences between them, in that context.
What do they represent?

What is the special role / effect they have on the above context? And how?

Why $1^n$ and $0^n$, and not other combinations?


Question: Best practice for avoiding module / theme / profile name clashes?
Answer: In my office we usually have a site key that gets used for most things.


Client: Acme Company &amp; Co
Key: acme
Site Folder: /path/to/WebServer/sites/acme
Custom Modules: acme_tweaks, acme_forms, acme_blocks, acme_settings
Theme: acme_theme
Repo: acme.git
etc...


For code that we re-use from site to site, we ensure that it's generalized and client ambiguous and then add it to some common modules that are part of our default module set - such as:


theme_tweaks
template_suggestions


Our rule is that unless it can be applied to all our client sites (at least moving forward) then it shouldn't go in theme_tweaks but in acme_tweaks etc.