Answer for How to evaluate a company if it is a Johnny-One-Note or not?

Hi Fadh,
 
In most (if not all) company’s annual report, they do write their major customers. For example, in CBIP’s 2014 annual report in page 119, it is written as below with the heading “Major Customers” : Revenue from one major customer, with revenue more than 10% of the Group revenue, amounts to
RM65,703,412 (2013 – RM158,582,174) arising from sales by the special purpose vehicles segment.
 
p/s: You’re welcome. Do read Warren Buffett’s letters to his shareholders too! They’re simply amazing reading materials. I’ll call his letters “Bible for Investing”.