Microsoft Word 2010
AutoFormat As You Type rules will automatically apply certain types of formatting to your document. Some of these settings can be quite convenient such as changing typed fractions with fraction characters and applying superscript to ordinals (4th, 5th, etc.) Other AutoFormatting may be confusing and/or unwanted such as automatically bulleting or numbering lists. To customize the AutoFormat As You Type rules:
If you do not want Word to automatically bullet or number lists, remove those options under the Apply as you type area of this window.