Here the link to the question: ExtensionPoints design and architecture with examples
The original question reads:
Can any one suggest a good (but simple) read on the design of ExtensionPoints for Asp.net?
That question is a polling for books to read and could be closed as either 'too broad' or 'recommend a tool, library or favorite off-site resource are off-topic for Programmers as they tend to attract opinionated answers and spam. Instead, describe the problem and what has been done so far to solve it.'
There is no problem presented in the question. It is a request for resources which lead to (poor) link only answers that rot over time.