To begin with, everything with php is done via a command system using brackets and slashes to tell the forum what formatting you want. There are buttons above your posts which give hotkey access, or you can just type the commands manually. The way php coding is done can be summed up as this: [command]text[/command]. Everything between the start command and end command (with the slash) will be affected by the command.
Examples
All commands should be entered with no spaces. If I typed them out without spaces, they would activate
Bold text
[ b]text[/b]
Italic text
[ i]text[/i]
underlined text
[ u]text[/u]
Text Color
[ color=#000000]text[/color]
---The six digits represent RGB coding ranging from 0 to F. So FF0000 is bright red, AA00AA is medium purple. This option can be fun when used, but can also make things harder to read when certain colors are used on certain forum backgrounds.
---These four can all be combined at will: Like this!
[ quote=Person]Executionus wrote: Quoted text
text[/quote]
---This one looks better if you hit Enter and start a new line with the text part. There is actually many other bits of data that can be added to a quote (post id, user id, time) that are included with the quote button, but these are not required for the visual effect.
Link text
[ url=insert link here]text[/url]
---Posting links in this manor looks better than just posting the naked link itself, plus it allows you to seamlessly insert outside links into a story without breaking from the flow. I've started using this in the Thirst Games for the character images.
Image
[ img]image link[/img]
---Some notes on this. The link MUST end in .jpg, .png, or some other image format, it has to be a direct image link with nothing else. It is also considered rude to link pictures that are too big and warp the forum, and is almost always frowned upon to put images in your signatures. This should not be overused to prevent lag and spam, which is a big reason why I chose to use links to pictures in the Thirst Games instead of directly posting images. Also most forums have a limit to images in a single post.
PS: Because I know this is gonna be asked, the picture I chose is from the MMD Street Hypnosis videos featuring Hatsune Miku and Kagamine Rin. If you haven't discovered Vocaloid MMD ENF content yet, well...you're welcome.
In addition to these fun little tidbits, posting new posts and threads has a whole bunch of options that we're not using. Technically we can upload and attach images directly to the forum, although I don't know what rules Viredae has on that sort of thing so I've just been using Imgur for mine. We can even create polls built into the forum itself, not requiring an outside source like what everyone had been using for contests so far (max ten choices). I plan to dust off the poll option and use it myself when the Thirst Games reaches its final 10 contestants. The options are located below the box where you type in the post text when you make a new post or thread.
Lastly we have the UserCP and its options. At the top-right corner of the page you can see your name. Clicking it brings up the link for your User Control Panel (called UserCP on most forums). There are a ton of options here, but for now I'm going to focus just on the profile (and especially avatars and signatures). You can enter data for yourself here, although mine is almost blank on purpose. Clicking the signature tab lets you type out a message that will appear at the bottom on every post you ever make. You can see mine down there with the links I put in it. It's highly recommended to keep these short and to not put in images, because they can turn a forum into spam central very quickly. The best use for them is just links to important content, such as an author's other stories or ENF websites they frequent.
Avatars are next, but these take work to actually make them show up. You will need to download the image you want to your computer and then edit it down in Photoshop or Paint down to exactly 90 pixels by 90 pixels. You also have to reduce quality down so that the filesize is less than 6 kb (which is harder than it sounds). I recommend using the gif image format for color reduction. Once your image is ready, you can go to your UserCP, click profile tab, click the avatar sub-tab, and then upload your avatar image with the button provided. If done right, this should now show up with your every post like mine does. It may take a few tries, trust me. I think I spent an entire half hour trying to get my avatar small enough in filesize in order to be accepted.
Avatars are personal representatives, and a good way to display your interests. In my case, I chose a woman's hands being restrained above her head, considering that half of my attraction to the genre centers around bound helplessness (which was probably very obvious given my stories).