Gets the subtype (S), such as GTS_PDFX, GTS_PDFA1 or ISO_PDFE1; null when missing.
S
GTS_PDFX
GTS_PDFA1
ISO_PDFE1
null
public string? Subtype { get; }
ISO 32000-2 Table 401 (required). A subtype that is not a name reads as missing with an OutputIntentInvalid diagnostic.
OutputIntentInvalid