Standard-tolerance SMD resistors use a 3-digit code to mark the resistance value on the part. The first two numbers will indicate the significant digits, and the third will be the multiplier. 'R' is used to indicate the position of a decimal point.
Similar to the three digit EIA, the four digit format uses the beginning values to indicate the significant digits while the last digit is the multiplier. 'R' is used to indicate the position of a decimal point. The four digit format allows for higher precision.
The EIA96 system of part marking is based on the EIA96 series of standard resistor values and is typically used on 1% tolerance parts. It uses three characters (two numbers and a digit) in which the numbers represent the value (34 = 34th value of the possible range) and the letter represents the multiplier.
