InDesign imports most character and paragraph formatting attributes from text files but ignores most page-layout information, such as margin and column settings (which you can set in InDesign). Note the following:
InDesign generally imports all formatting information specified in the word-processing application, except information for word-processing features not available in InDesign.
InDesign can add imported styles to its list of styles for
the document. A disk icon appears
next to imported styles. (See Convert Word styles to InDesign styles.)
The import options appear when you select Show Import Options in the Place dialog box, or when you import an Excel file. If Show Import Options is deselected, InDesign uses the import options last used for a similar document type. The options you set remain in effect until you change them.
If InDesign cannot find a filter that recognizes a file by either its file type or file extension, an alert message appears. For best results in Windows, use the standard extension (such as .doc, .txt, .rtf, or .xls) for the type of file you’re importing. You may need to open the file in its original application and save it in a different format, such as RTF or text-only.
For more information on import filters, see the Filters ReadMe PDF file located in the InDesign application folder.