Position Code Format

I am HRIS manager for two companies that recently merged. Thankfully, both companies used Lawson HR/Payroll, so it was a matter of combining tables/codes and deciding on common pay practices. Each company had a unique method of formatting their position codes and we did not change them when merging, so now our position codes are a mixture of both. We now want to change them to a common format, and this gives us the opportunity to avoid some of the issues that both companies experienced with our attempts at smart-coding. Does anyone use a format that you feel has worked well for your company? Do you try to include elements of the position definition in the coding, or do you feel this is too difficult? Do you use alpha, numeric, or a combination? We would welcome any insight!