https://www.infopathdev.com:443/forums/39.aspxNew to InfoPath? Search to see if your question has already been answered. If it has not, then ask it here or the appropriate topic forum.enCommunityServer 2007 SP3 (Build: 31118.962)https://www.infopathdev.com:443/forums/thread/2802.aspxWed, 19 Jul 2006 20:44:03 GMT033a2e2d-04e2-4a9d-be01-a4634161eefd:2802lightman0https://www.infopathdev.com:443/forums/thread/2802.aspxhttps://www.infopathdev.com:443/forums/commentrss.aspx?SectionID=39&PostID=2802I'm researching it because I wanted to verify that I was using the same XML validation engine in the program I'm using to write my XML schemas...Stylus Studio XML Pro.https://www.infopathdev.com:443/forums/thread/2801.aspxWed, 19 Jul 2006 18:15:45 GMT033a2e2d-04e2-4a9d-be01-a4634161eefd:2801Matt Faus0https://www.infopathdev.com:443/forums/thread/2801.aspxhttps://www.infopathdev.com:443/forums/commentrss.aspx?SectionID=39&PostID=2801You'll probably want to go with DOM. Why does this matter to you? Just curious or what?https://www.infopathdev.com:443/forums/thread/2800.aspxWed, 19 Jul 2006 14:57:38 GMT033a2e2d-04e2-4a9d-be01-a4634161eefd:2800lightman0https://www.infopathdev.com:443/forums/thread/2800.aspxhttps://www.infopathdev.com:443/forums/commentrss.aspx?SectionID=39&PostID=2800Thanks for the 'Welcomes' & responses. <br /><br />OK I got it down to the MSXML thing...now I'm wondering if there's a certain version of MSXML that is used by default....for example MSXML 4.0 DOM Parser, or MSXML 4.0 SAX Parser, or something else. Any thoughts?https://www.infopathdev.com:443/forums/thread/2799.aspxWed, 19 Jul 2006 06:55:38 GMT033a2e2d-04e2-4a9d-be01-a4634161eefd:2799Patrick Halstead0https://www.infopathdev.com:443/forums/thread/2799.aspxhttps://www.infopathdev.com:443/forums/commentrss.aspx?SectionID=39&PostID=2799Hi Lightman and welcome,<br />MSXML is what is used for InfoPath 2003. There is other conditional validation that is done on top of the XML datatype/structure validation, but that doesn't prevent loading. MSXML is your ticket. As Matt suggests, InfoPath 2007 may use System.XML since it is now managed OM (but I have a hunch they may still be using MSXML internally... not sure). Hope this helps!https://www.infopathdev.com:443/forums/thread/2798.aspxTue, 18 Jul 2006 16:13:57 GMT033a2e2d-04e2-4a9d-be01-a4634161eefd:2798Matt Faus0https://www.infopathdev.com:443/forums/thread/2798.aspxhttps://www.infopathdev.com:443/forums/commentrss.aspx?SectionID=39&PostID=2798Hi lightman and welcome to the forum!<br /><br />What exactly do you mean when you say "validation engine"? The schema files for the Main DOM and all of the 2DSs are stored within the XSN and I'm sure InfoPath uses something from the System.Xml namespace to do the validation. What exactly are you trying to figure out?https://www.infopathdev.com:443/forums/thread/1426.aspxTue, 18 Jul 2006 15:47:30 GMT033a2e2d-04e2-4a9d-be01-a4634161eefd:1426lightman0https://www.infopathdev.com:443/forums/thread/1426.aspxhttps://www.infopathdev.com:443/forums/commentrss.aspx?SectionID=39&PostID=1426Does anyone know what the default validation engine is that InfoPath uses to validate a document?