# PDF/A-3: The Better Container for Electronic Documents > The Portable Document Format, or PDF is the most commonly used document format for business applications. PDF/A-3 permits the embedding of files of any format. This article gives an overview of the advantages of PDF/A-3 as an electronic container. - **Author:** Bjoern Meyer - **Published:** 2020-07-23 - **Modified:** 2025-11-16 - **Description:** PDF is the most commonly used document format for business applications. This article gives an overview of the advantages of PDF/A-3 as an electronic container. - **4 min read** (715 words) - **Tags:** - ASP.NET - Electronic Paper - Hybrid Archiving - PDF - PDF/A - Release - Sneak Peek - ZUGFeRD - **Web URL:** https://www.textcontrol.com/blog/2020/07/23/pdfa-the-better-container-for-electronic-documents/ - **LLMs URL:** https://www.textcontrol.com/blog/2020/07/23/pdfa-the-better-container-for-electronic-documents/llms.txt - **LLMs-Full URL:** https://www.textcontrol.com/blog/2020/07/23/pdfa-the-better-container-for-electronic-documents/llms-full.txt --- ### The Beginning The **Portable Document Format**, or PDF is the most commonly used document format for business applications. Back in 1990, Adobe's co-founder Dr. John Warnock published a white paper essentially describing the need for the PDF format: > What industries badly need is a universal way to communicate documents across a wide variety of machine configurations, operating systems and communication networks. These documents should be viewable on any display and should be printable on any modern printers. If this problem can be solved, then the fundamental way people work will change. > > [Dr. John Warnock](https://theblog.adobe.com/evolution-digital-document-celebrating-adobe-acrobats-25th-anniversary/), Co-founder Adobe In a nutshell, the advantage of PDF documents is the multi-platform compatibility. A document such as a tax form or invoice can be send to any recipient who is able to read, complete or print it. Because of available editing restrictions (and later electronic signatures), a PDF has been handled very much like printed paper and received a similar status in business processes. ### Electronic Data Interchange **Electronic Data Interchange**, better known as EDI, existed since the early 1970s to communicate data between applications. The idea was to save money by replacing paper based documents and therefore, manual paper processes such as sorting, archiving and printing. The reality of this approach was that more paper documents have been produced and sent as paper documents were maintained in parallel with EDI data. Legal restrictions and user experience require most data (for example invoices) to be human-readable. In theory, the PDF document is the perfect format to replace printed paper. It is easy to send, easy to read on all machines, can be searched and is good for archiving processes. But the machine-readable data is missing. The software industry tried to solve this issue by recognizing content in PDF documents (very similar to OCR processes) to give documents a context (*Is this document an invoice?*) and to match content with expected fields (*invoice number, addresses, products, ...*). ### From Electronic Paper to Container In the most recent iteration of PDF/A specifications, PDF/A-3 added a significant change to all predecessors. PDF/A-3 (ISO 19005-3:2012) permits the embedding of files of any format (including XML, MS Word and proprietary binary formats). This change allows the progression from *electronic paper* to an *electronic container* that holds the human and machine-readable versions of documents. Now, the human-readable version can be ignored by applications reading the data of the document. Applications can extract the machine-readable portion of the PDF document in order to process it. A PDF/A-3 document can contain an unlimited number of embedded documents for different processes. According to the specification, software applications can extract embedded files without explicit knowledge of the PDF document itself. ### Create and Extract Embedded Files Technically, that is not an easy process. With TX Text Control X19 (29.0), we will provide PDF features to create documents with embedded files and also to extract embedded files from these electronic containers.The following code creates a PDF document with an embedded XML document: ``` var sData = File.ReadAllText("data.xml"); TXTextControl.EmbeddedFile file = new TXTextControl.EmbeddedFile("data.xml", sData, "") { MIMEType = "text/xml", RelationShip = "Alternative" }; TXTextControl.SaveSettings saveSettings = new TXTextControl.SaveSettings() { EmbeddedFiles = new TXTextControl.EmbeddedFile[] { file } }; textControl1.Save("myinvoice.pdf", TXTextControl.StreamType.AdobePDFA, saveSettings); ``` When opened in Adobe Acrobat Reader, you can find the embedded files in the *Attachments* sidebar tab: ![PDF/A-3 with TX Text Control](https://s1-www.textcontrol.com/assets/dist/blog/2020/07/23/a/assets/acrobat-pdfa3.webp "PDF/A-3 with TX Text Control") TX Text Control cannot only be used to create those documents, but to import and extract the embedded files as well. The following code shows how to extract the XML data from the PDF document: ``` TXTextControl.LoadSettings ls = new TXTextControl.LoadSettings(); ls.PDFImportSettings = TXTextControl.PDFImportSettings.LoadEmbeddedFiles | TXTextControl.PDFImportSettings.LoadMetadata; textControl1.Load("myinvoice.pdf", TXTextControl.StreamType.AdobePDF, ls); var dataXml = Encoding.Unicode.GetString((byte[])ls.EmbeddedFiles[0].Data); ``` ### TX Text Control Covers Complete PDF Workflow The *EmbeddedFiles* property contains an array of all files embedded in the PDF document. TX Text Control can be used to cover the complete PDF document workflow from creating the document to processing incoming documents in business applications. Combined with the powerful template-based document creation engine, TX Text Control provides developers the complete solution to handle PDF documents in business processes. --- ## About Bjoern Meyer As CEO, Bjoern is the visionary behind our strategic direction and business development, bridging the gap between our customers and engineering teams. His deep passion for coding and web technologies drives the creation of innovative products. If you're at a tech conference, be sure to stop by our booth - you'll most likely meet Bjoern in person. With an advanced graduate degree (Dipl. Inf.) in Computer Science, specializing in AI, from the University of Bremen, Bjoern brings significant expertise to his role. In his spare time, Bjoern enjoys running, paragliding, mountain biking, and playing the piano. - [LinkedIn](https://www.linkedin.com/in/bjoernmeyer/) - [X](https://x.com/txbjoern) - [GitHub](https://github.com/bjoerntx) --- ## Series - [Text Control Announces PDF/A-3 Support: The Future of Electronic Invoices](https://www.textcontrol.com/blog/2020/07/21/text-control-announces-pdf-a-3-support/llms.txt) - **PDF/A-3: The Better Container for Electronic Documents** (this article) --- ## Related Posts - [Text Control Announces PDF/A-3 Support: The Future of Electronic Invoices](https://www.textcontrol.com/blog/2020/07/21/text-control-announces-pdf-a-3-support/llms.txt) - [X19 Sneak Peek: Validating ZUGFeRD / Factur-X Invoices with TX Text Control](https://www.textcontrol.com/blog/2020/11/10/x19-sneak-peek-validating-zugferd-factur-x-invoices-with-tx-text-control/llms.txt) - [Why Structured E-Invoices Still Need Tamper Protection using C# and .NET](https://www.textcontrol.com/blog/2026/03/24/why-structured-e-invoices-still-need-tamper-protection-using-csharp-and-dotnet/llms.txt) - [PDF is Dead, Long Live PDF: Why PDF Remains Relevant in a Changing Digital World](https://www.textcontrol.com/blog/2024/10/20/pdf-is-dead-long-live-pdf-why-pdf-remains-relevant-in-a-changing-digital-world/llms.txt) - [Create PDF File with .NET C#](https://www.textcontrol.com/blog/2024/10/17/create-pdf-file-with-net-c-sharp/llms.txt) - [Store Documents as PDF/A using C# - A Future-Proof Archiving Format](https://www.textcontrol.com/blog/2023/10/24/store-documents-as-pdfaa-using-csharp-a-futureproof-archiving-format/llms.txt) - [Use PDF.js to Render PDF Documents within the Document Viewer](https://www.textcontrol.com/blog/2023/03/18/use-pdfjs-to-render-pdf-documents-within-the-document-viewer/llms.txt) - [TX Text Control 30.0 Preview: Inserting SVG Images](https://www.textcontrol.com/blog/2021/07/13/text-control-30-preview-inserting-svg-images/llms.txt) - [Creating ZUGFeRD Compliant PDF Invoices in C#](https://www.textcontrol.com/blog/2021/02/03/creating-zugferd-compliant-pdf-invoices-in-csharp/llms.txt) - [Extract ZUGFeRD/Factur-X XML Attachments from Adobe PDF/A-3b Documents](https://www.textcontrol.com/blog/2021/01/18/extract-zugferd-facturx-attachments-from-adobe-pdf-documents/llms.txt) - [X19 Sneak Peek: Storing Document Revisions in PDF/A-3b](https://www.textcontrol.com/blog/2020/11/03/x19-sneak-peek-saving-document-versions-in-pdfa-3b/llms.txt)