Spelling out abbreviations

[Nancy Allison]

I'm editing a document that is peppered with abbreviations and capitalized terms. My question is about whether you capitalize the terms when you spell out an abbreviation. Here are some examples from my document:

---Develop a utility containing Risk Control Self Assessments (RCSAs).  

---Evaluate the Probability of Default (PD).

In both instances, I googled each term and found documents that spelled them out initially with lowercase letters. However, I bet if I kept looking I'd find docs online that do use initial caps -- examples found on the web prove very little!

I want to use lowercase letters for these terms. What would you do? Does any reference book you have handy deal with this? I am working in a barren cubicle with no reference materials a-tall.