Linearized PDF has existed as a concept since v1.2 which I think was released in 1996. You can see it mentioned in the v1.4 spec at https://www.adobe.com/conte

Linearized PDF has existed as a concept since v1.2 which I think was released in 1996. You can see it mentioned in the v1.4 spec at https://www.adobe.com/content/dam/acom/en/devnet/pdf/pdfs/pdf_reference_archives/PDFReference.pdf https://www.adobe.com/content/dam/acom/en/devnet/pdf/pdfs/pd... [follow the link from the contents].