Coming from #3688 the page explaining "suggested age" seems to be so minimal that it's hard to understand how it's meant to be used: https://schema.org/suggestedAge For example, it says "The age or age range for the intended audience or person, for example 3-12 months for infants, 1-5 years for toddlers." but it doesn't say how that would be expressed in JSON. While it links https://schema.org/QuantitativeValue if I go there, I can find this JSON example:

{
    "@type": "QuantitativeValue",
    “minValue”: 2500,
    “maxValue”: 7500,
    "unitCode": "USD"
}

This would suggest that a suggested age may be intended to look like this:

{
    "@type": "QuantitativeValue",
    “minValue”: 1,
    “maxValue”: 5,
    "unitCode": "???? year or what do I put here??"
}

However, this neither explains what unitCode to use for years and months, nor is it that quick to find given how complex QuantitativeValue is. If I follow two other links (which already seems like a lot to find this basic information) I find the explanation The unit of measurement given using the UN/CEFACT Common Code (3 characters) or a URL but again no common examples, particularly also not for months or years, and also not any link to any page that has a table with codes.

Furthermore, it's not obvious from any of the pages whether the upper bound of "suggestedAge" is meant to be optional. Based on this third-party page it is: https://developers.google.com/search/docs/appearance/structured-data/product-variants This seems like vital information.

I therefore suggest that a few JSON-LD examples are added to https://schema.org/suggestedAge that 1. show how to specify a range in months, 2. show how to specify a range in years, and 3. show that the upper bound can be omitted.