File Types

Symbol	Type	Notes
	.HTML or .HTM (Metadata)	An Metadata file is a special type of HTML file used on the TTNWeb that provides metadata, or context information, such as author, topic, related subjects, etc., about a particular document.
	.CGM (Computer Graphics Metafile)	A graphics file viewable from most applications able to display multiple graphics formats. CGM files should be viewable on most platforms.
	.COM (IBM PC-Compatible Command)	A PC executable module that can be executed after downloading by typing the name of the file. (This would typically be done in a DOS session.) This file type will not work with non PC-compatible computers.
	.DBF (Dbase)	A Dbase database file. Most professional database applications have converters for Dbase files.
	.DOC (Word)	A document stored in Microsoft Word format. Microsoft Word files can be viewed through Microsoft Word, or through programs that convert from Word format. Although the Word files on TTN are mostly generated from Windows machines, they should be viewable from MacIntosh systems. If you have trouble viewing a Word document from TTN, it may be because the document was generated in a later version of Word than the one on your machine. If you do not have Word, you can download a Word viewer from the web.
	.EXE (IBM PC-Compatible Executable)	A PC executable module that can be executed after downloading by typing the name of the file. (This would typically be done in a DOS session.) This file type will not work with non PC-compatible computers.
	.GIF (Graphics Interchange Format)	A Graphics Interchange Format image. This file should work with any system capable of viewing graphics from the web, using viewers such as Netscape.
	.HTML or .HTM (Hypertext Markup Language)	An HTML file that may be viewed within a Web browser such as Netscape.
	.MDB (Access Database)	Microsoft Access database files. Can only be used by systems capable of viewing Microsoft Access files.
	.MOV (QuickTime File)	Apple Quicktime files. Can only be used by systems capable of viewing Apple Quicktime Files.
	.PDF (Portable Document Format)	An Adobe Acrobat file requires the use of an Acrobat reader. The latest reader is available from Adobe, free of charge. TTN has files created for Acrobat Reader version 3.0 and version 4.0. Although many of the older PDF files are still readable with Acrobat Reader 2.1, newer PDFs can only be read with version 3.0 or version 4.0. If you have problems reading some of the newer PDF files, check and make sure you are using the latest Acrobat viewer. Viewers are available for UNIX, Windows, MacIntosh and DOS.
	.PDF (Portable Document Format)	This is also an Adobe Acrobat file (see above), but Acrobat files with this icon represent documents that were obtained directly from the Federal Register . While non-Federal Register documents do represent the finalized content of a document, minor changes can be introduced between finalized EPA submission and the publication of the Federal Register version. The Federal Register version represents the official version of the document, and supersedes all other versions of that document, regardless of source.
	.PPT (PowerPoint)	A Microsoft PowerPoint file. Can only be used by systems capable of viewing Microsoft PowerPoint files. If you do not have PowerPoint, you can download a viewer from the web. There are viewers for both IBM-compatible and MacIntosh PCs.
	.PRE (Freelance Graphics)	A Lotus Freelance Graphics file. Can only be used by systems capable of viewing Lotus Freelance Graphics files. If you do not have Freelance, you can download a viewer from the web. There are viewers for both IBM-compatible and MacIntosh PCs.
	.PUB (MS Office Publisher)	A document created by Microsoft Office Publisher. Microsoft Office Publisher documents can only be viewed with Microsoft Publisher software. The files could also be downloaded and taken to a commercial printer who uses Microsoft Office Publisher.
	.TXT (Text)	ASCII text files that can be read on the screen or downloaded and processed with a word processor or text editor. These files are should be viewable from virtually any system.
	.WK4 (Lotus 1-2-3)	Can only be used by systems capable of viewing Lotus 1-2-3 files. If you do not have 1-2-3, you can download a viewer from the web. There are viewers for both IBM-compatible and MacIntosh PCs.
	.WPD (WordPerfect)	A Corel WordPerfect file. The files downloadable from TTN are usually in either 6.2 format (usually) or 5.1 format (occasionally). These formats are supported by a number of versions of WordPerfect, which is available for UNIX, Windows, MacIntosh and DOS. Additionally, many word processors other than WordPerfect can read WordPerfect files (although they may not convert the formatting properly).
	.XLS (Excel)	Can only be used by systems capable of viewing Microsoft Excel files. If you do not have Excel, you can download a viewer from the web. There are viewers for both IBM-compatible and MacIntosh PCs.
	.ZIP (PKZip)	PKZip compressed files. "PKUNZIP.EXE" is a dearchiver program used to dearchive compressed (ZIP) files that are downloaded from the TTNWeb. The shareware version is available from our file utilities page for IBM PC-compatibles. There are no versions of PKZip for MacIntosh or Unix. Windows programs, such as WinZip can also be used.

TTN Web Disclaimers

Listing of file types associated with products created by commercial vendors does not constitue a guarantee or endorsement of the companies or their products by TTNWeb or the EPA. For more information, please see the TTN disclaimer page.