If you know how to use HTML, you can use an abbreviated list of HTML tags in your posts, including a, b, blockquote, center, em, i, li, ol, pre, small, strike, strong, sub, sup, and ul. You can just type them into the compose/comment box.
To add italics, for example, you would type: <em>italicized word</em>
which shows as: italicized word
To add a link to example.com you would type: <a href="http://example.com">here is a link to example.com</a>
which shows as: here is a link to example.com
If you use a modern browser, you'll see B/I/link buttons below the compose/comment box that you can use to add basic formatting. To make a link using the button, you highlight the word or phrase you want to be the link text (like the phrase "here is a link to example.com" above), click the link button, and type or paste the URL into the box that appears.
Here's a short screencast showing how to use the buttons to insert HTML for you:
Never in a front page post. In a Metafilter post, it's absolutely against the rules to link to your own site, to a site that you host or contribute to substantially, or to a site of someone who is a close friend or relative of yours. Some more detail is in this MetaTalk comment. People who self-link in front page posts on MetaFilter will have their posts removed and their account banned. Transparency and honesty are important to the community and we rely on users to abide by the guidelines and participate honestly.
Likewise, Ask MetaFilter questions that seem to be thinly veiled promotion or self-promotion will be removed. Questions that seem to be being asked with the intent to promote a poster's product or service, or client/friend's product or service, will be removed and the participating accounts banned. If you are unsure about a specific example, please contact us.
Linking to your own site in an Ask MetaFilter question is only okay if it has something specific to do with the question being asked and is necessary for people to provide an answer, for example "Can you look at my logo and tell me why everyone thinks it looks like a devil?" or "What else do I need to do to this website to make it ADA compliant?" (Even then, an extra-safe move is to link your site on your profile page and tell people they can see it by going through your profile.) Other self-links will be removed. AskMe posts that look like link-heavy MeFi posts or other promotional posts with a question tacked to the end of it are not okay.
In comments, in well-defined circumstances, self-links can be okay. Including a link to your own site in a Metafilter comment is okay provided that it has some relevance to the topic being discussed, and you clearly disclose your affiliation to the site or site-owner, and this type of comment is not your only form of site participation. Random off-topic insertions of self-links into other posts are discouraged and such links may be removed. Similarly, linking to your own content in AskMe answers is okay to do occasionally and with disclosure. People who seem to be self-linking continually, or seemingly with spammy intent may have their content removed and their account banned.
What is the policy on URL shortening or using link shorteners?
The short policy is "please don't use them." Mods will expand short URLs when they see them. There is a difference, however, between site-specific URL shorteners like youtu.be and nytim.es and link shortening sites such as is.gs and j.mp, where the former is okay if not preferred while the latter is something we'd prefer people avoid. People who use link shorteners as a way of sketchily hiding affiliate codes may risk having their account banned. (tags: linkslinkshortenersshortlink ) July 25, 2011 - permalink - back to questions