PDF/A is an ISO-standardized subset of PDF designed for long-term archival of electronic documents. The "A" stands for Archive. PDF/A ensures a document can be reproduced exactly the same way in 50-100 years, regardless of future software changes. Key requirements: all fonts must be embedded (no references to external fonts), all content must be self-contained, and certain interactive features (JavaScript, encryption, external links) are prohibited.
There are multiple PDF/A versions: PDF/A-1 (based on PDF 1.4, most restrictive), PDF/A-2 (based on PDF 1.7, supports layers and JPEG 2000), PDF/A-3 (allows any file type as embedded attachment). Choosing between them depends on your archival requirements. Government agencies, hospitals, and legal firms often mandate PDF/A for record-keeping compliance.
Converting to PDF/A typically requires specialized software: Adobe Acrobat Pro (Preflight → Convert to PDF/A), LibreOffice (Export as PDF/A), or callas pdfToolbox. PDFs with JavaScript, embedded video, or external references can't always be perfectly converted to PDF/A. FileCurve's standard PDF tools don't currently include PDF/A conversion.