Although the specs for HTML call for tags to be in upper case, your browser won't know the difference, even if this is how the standard is written. Recall that in HTML, element and attribute names are case-insensitive. This convention is meant to encourage readability. I would love to see this broken down into newspaper classified recruiting costs vs. headhunter recruiting costs.
Every company has different ways of calculating it.
I recommend that you create a spreadsheet model listing all of the variables, then select which ones a typical company might use. I would like to use it with our board of directors for their education. For 18 years I ran a legal transcription business out of my home. I worked with courts, court reporting offices and for individual court reporters. When court reporting became computerized, I lost my client base and went into medical transcription and then worked for a sheriff's department in law enforcement records for five years.