This contribution proposes that the shutter interval information (SII) SEI message already specified in HEVC be adopted in the next version of VSEI. A functionally equivalent SII SEI message is also already specified in AVC. The SII SEI message indicates the shutter interval for the associated video source pictures prior to encoding, e.g., for camera-captured content, the shutter interval is the amount of time that an image sensor is exposed to produce each source picture. Shutter interval information can be useful for several use cases, for example: enabling backwards compatibility of high frame rate (HFR) bit streams with receivers that support only standard frame rate (SFR) bit streams such as specified in ETSI TS 101 154 and ATSC A/341; prediction of subjective quality of motion; frame rate conversion; and detection of non-camera-captured content such as screen captures and computer-generated content. Additional descriptions, methods, and showcase VTM software is provided to illustrate the use of the SII SEI message with backwards compatible HFR bit streams.