A sequence of ranges to specify the repetition can also be used in a special group called repeating unit with repetition ranges. See the figure below for an example.
In this example, the repetition range is 3,5-7. The repetition count for the included structure can be 3,5,6, or 7. The repetition range can contain ranges and numbers, these elements must be separated by commas. For example, 3, 5-7.
{primary} Warning: When interpreting the range of repeating units (cases: enumerating a Markush structure, counting the number of enumerated structures, search, etc.), it is possible that not the whole range is used, only a limited set of repetition counts. From versions 25.3.0 and Radium.2 (LTS), these limitations have been changed. For details, see repeating unit limitations.
To draw a repeating unit with repetition ranges, follow the steps below.