1.1 This specification (see Note 1) covers grades of fuel oil intended for use in various types of fuel-oil-burning equipment under various climatic and operating conditions. These grades are described as follows: 1.1.1 This specification covers grades of fuel oil intended for use in various types of fuel-oil-burning equipment under various climatic and operating conditions. These grades include the following: Grades No. 1 S5000, No. 1 S500, No. 2 S5000, and No. 2 S50