For most IDT parts (excluding some clocking devices), tape and reel products include the number '8' as a suffix. For example, the 7206L15J8 is a tape and reel part, the 7206L15J is not.

For some timing devices, you may see the 'T' suffix indicating the tape and reel.

Since these methods are not consistently used (due to various product acquisitions throughout the years), it's advisable to review the datasheet to confirm the tape and reel part number.