Reserves are only the part of those recoverable resources that will be developed through identified and approved development projects. Because the evaluation of "Reserves" has a direct impact on the company or the asset value, it usually follows a strict set of rules or guidelines (even though loopholes are commonly used by companies to inflate their own share price). The most common guidelines are the SPE PRMS guidelines, the SEC Rules, or the COGE Handbook. Government may also have their own systems, making it more complicated for investors to compare one company with another.