WARNING

In the case where all three properties are set to something other than auto -- or, to borrow a term from the CSS specification, when these formatting properties have been over-constrained -- then margin-right is always forced to be auto. This means that if both margins and the width are set to 100px , then the right margin will be set by the user agent to auto:

list-style-type Values disc | circle | square | decimal | upper-alpha | lower-alpha | upper-roman | lower-roman | reflow previous content to accommodate things that happen later in the document. In other words, if an image is floated up into a previous paragraph, it may simply overwrite whatever was already there. On the other hand, the user agent may handle the situation by flowing content around the float, even though doing so isn't required behavior. Either way, it's probably a bad idea to count on a particular behavior, which makes the utility of negative margins on floats rather limited. Hanging floats are probably fairly safe, but trying to push an element upward on the page is generally a bad idea. usually first attempt to support. Given that there were some verygood positioning implementations on the horizon as the book was beingcompleted, we felt it worthwhile to give readers a glimpse ofwhat's coming soon -- or, if you're reading this booka year or three after its publication, what can be done. You may notice that, unlike other chapters, almost none of thefigures in this chapter was generated with a web browser. This issomething of a statement about the reliability and consistency ofpositioning implementations at the time of this writing: not one of