Add FAQ and category clarification.

Closes #93.
Closes #91.
Closes #88.
Closes #87.
Closes #83.
Closes #78.
Closes #64.

README.mdown

@@ -28,6 +28,7 @@ Table of Contents
 - [Resources and Bundles](#resources)
 - [Adding the Framework to a Third-Party Application](#third_parties)
 - [Developing the Framework as a Dependent Project](#first_parties)
+- [FAQ](#faq)
 - [License](#license)
 
 <a name="existing_solutions" />
@@ -235,6 +236,14 @@ Whenever you add new source to the framework you must decide whether to expose t
 not. To modify a header's scope you will follow the same process as Step 2. By default a header's
 scope will be "Project", meaning it will not be copied to the framework's public headers.
 
+#### An Important Note on Categories
+
+Using a category should be a **necessity**, not a convenience, when distributing a framework.
+
+Frameworks, by their very nature, obscure a lot of implementation details, very likely leading to severe run-time tomfoolery as symbols get overwritten and your client's app starts performing in wonderfully novel ways (much to their users' chagrin).
+
+If you **absolutely** ***must** use categories, please check out the [FAQ](#faq) in order to avoid having your clients encounter linker problems when attempting to use them.
+
 ### Step 4: Disable Code Stripping
 
 We do not want to strip any code from the library; we leave this up to the application that is
@@ -639,6 +648,53 @@ Build your application and verify a couple things:
 - Your framework should be linked into the application.
 - You shouldn't get any compiler or linker errors.
 
+<a name="faq" />
+FAQ
+===
+
+How do I resolve 'unrecognized selector sent to instance' linker errors?
+------------------------------------------------------------------------
+
+- **The recommended solution** is to use [NimbusKitBasics' NI_FIX_CATEGORY_BUG](https://github.com/NimbusKit/basics#avoid-requiring-the--all_load-and--force_load-flags) whenever possible. This solution minimizes the amount of your framework that will need to be linked into the client's app binary.
+- [Breakdown of solutions](http://stackoverflow.com/a/22264650/65455) from [Mecki](http://stackoverflow.com/users/15809/mecki) on stackoverflow.
+
+How do I include Third-Party Libraries in my Framework?
+-------------------------------------------------------
+
+Don't.
+
+Ok, you can, but it's a bitch to do correctly - and it's really important that you do it correctly.
+
+The scenario you want to avoid is the following:
+
+- You've linked some third-party library in your code (e.g. [NimbusKit's Markdown](https://github.com/nimbuskit/markdown)).
+- A client using your framework also wants to use NimbusKit's Markdown.
+- Their app fails to build due to duplicate symbol linker errors.
+- Client gets incredibly frustrated with your framework and uses something else.
+
+Solutions, in order of easiest-to-most-difficult:
+
+### Pure framework build (no third-party libraries included) + library source distribution
+
+Bundle any libraries that your framework uses alongside your framework when you distribute it (e.g. distribute a zip file with your built .framework and a third-party folder containing the source for all libraries used). Make it clear in your setup guide that the additional libraries will also need to be compiled into the client's app.
+
+This:
+
+- gives the client the flexibility to use their own version of the library;
+- encourages proper attribution and license redistribution of any open source code you're using;
+- and, most importantly, ensures that the client will not encounter duplicate symbol linker errors.
+
+### Symbol Prefixing
+
+This is hard to do correctly and requires meticulous ongoing care to ensure that no symbols ever slip through the build process.
+
+This solution allows you to completely guarantee that a given version of a third-party library will be used by your framework. It also allows you to distribute a single .framework, easing the setup and versioning process.
+
+Some approaches to symbol prefixing:
+
+- High level overview by [featherless](http://twitter.com/featherless) on StackOverflow: [http://stackoverflow.com/questions/11512291/prefix-static-library-ios/19341366#19341366](http://stackoverflow.com/questions/11512291/prefix-static-library-ios/19341366#19341366).
+- [Avoiding Dependency Collisions in an iOS Library](http://pdx.esri.com/blog/2013/12/13/namespacing-dependencies/) on esri.com.
+
 <a name="license" />
 License
 =======