I just noticed that LJ is fiddling with their CSS again, changing the way that the same post is displayed on different pages. When you view the previous post on your friends page or the LJ calendar page, it looks precisely how I meant it to look. However, when you view the post itself with comments, LiveJournal has decided to italicize all blockquoted text despite the lack of italic tags and the lack of intention on my part to make that text italicized. That means that, if I don't want the blockquoted text italicized, then I have to code my posts differently.
This is the code that is required to blockquote text. Note that CSS can be used to change how blockquoted text is displayed. For instance, CSS can be used to make all blockquoted text italic by default; and different LJ pages can (and do) have different CSS settings. (Also, I just noticed that LJ changes the default blockquote margin sizes along with the italics.)
<blockquote>This text is in a blockquote.</blockquote>
Below is a block of code which attempts, through the use of margins, to simulate a plain, unaltered blockquote without using the blockquote tags (as they may have been altered with CSS):
<div style="margin-right: 1cm; margin-left: 1cm; margin-top: 1em; margin-bottom: 1em;">This text has been formatted with margins.</div>
Please note that the right and left margins are one CM (centimeter), while the top and bottom are one EM (typographic measure). Without CSS alterations, those two blocks of code will normally be formatted pretty much the same way.