use superscript for m/s^2

Author: npdoty

index.bs

@@ -416,9 +416,9 @@ The static {{DeviceMotionEvent/requestPermission()}} operation, when invoked, mu
 
 In the {{DeviceMotionEvent}} events fired by the user agent, the following requirements must apply:
 
-The {{DeviceMotionEvent/acceleration}} attribute must be initialized with the acceleration of the hosting device relative to the Earth frame, expressed in the body frame, as defined in [[#deviceorientation|deviceorientation Event]] section. The acceleration must be expressed in meters per second squared (m/s2) and must not be more precise than 0.1 m/s2.
+The {{DeviceMotionEvent/acceleration}} attribute must be initialized with the acceleration of the hosting device relative to the Earth frame, expressed in the body frame, as defined in [[#deviceorientation|deviceorientation Event]] section. The acceleration must be expressed in meters per second squared (m/s<sup>2</sup>) and must not be more precise than 0.1 m/s<sup>2</sup>.
 
-Implementations that are unable to provide acceleration data without the effect of gravity (due, for example, to the lack of a gyroscope) may instead supply the acceleration including the effect of gravity. This is less useful in many applications but is provided as a means of providing best-effort support. In this case, the {{DeviceMotionEvent/accelerationIncludingGravity}} attribute must be initialized with the acceleration of the hosting device, plus an acceleration equal and opposite to the acceleration due to gravity. Again, the acceleration must be given in the body frame defined in [[#deviceorientation|deviceorientation Event]] section and must be expressed in meters per second squared (m/s2) and must not be more precise than 0.1 m/s2.
+Implementations that are unable to provide acceleration data without the effect of gravity (due, for example, to the lack of a gyroscope) may instead supply the acceleration including the effect of gravity. This is less useful in many applications but is provided as a means of providing best-effort support. In this case, the {{DeviceMotionEvent/accelerationIncludingGravity}} attribute must be initialized with the acceleration of the hosting device, plus an acceleration equal and opposite to the acceleration due to gravity. Again, the acceleration must be given in the body frame defined in [[#deviceorientation|deviceorientation Event]] section and must be expressed in meters per second squared (m/s<sup>2</sup>) and must not be more precise than 0.1 m/s<sup>2</sup>.
 
 The {{DeviceMotionEvent/rotationRate}} attribute must be initialized with the rate of rotation of the hosting device in space. It must be expressed as the rate of change of the angles defined as {{DeviceOrientationEvent/alpha}} (x axis), {{DeviceOrientationEvent/beta}} (y axis), {{DeviceOrientationEvent/gamma}} (z axis). Each attribute must be expressed in degrees per second (deg/s) and must not be more precise than 0.1 degrees per second.