Punctuation:  

I use (parenthesis) as normal, usually an aside from the narrator.  {Paraparentheses} represent the third wall, or outside the narration, usually an aside from the author, except when it's Mind-Mind communication {Mostly Basiatis}  [Brackets] typicly mean text, or script on paper, signs, or screens to differentiate it from "Quotes", which are spoken.

I've also recently started using "Sound Effects," or weird onomatopoeia, such as "Hnh," and all the variations on a sigh.  There's no standard set, any more than there are standard wordless utterances, or spellings for the sound of a slice of buttered toast hitting the carpet, for example.

Story Codes:

I don't use the standard set, (if there is one) so here's a helpful guide to let you know what you're getting into.

MFmfBGbg...  Just a rundown of the characters involved by gender, and approximate maturity.  M and F denote adult men, and women, m/f are adolescents, and b/g children.  I added B and G for boys and girls on the cusp of puberty, as well as some non-humans who are adult, but physically pre-pubertal.  I intend no sexism by putting the males first, the order is completely arbitrary, but may have some meaning to me on a by-case basis.  

TtIi... means trans/intersex/genders of various ages, and stages.  Transsexual means intentional moving between male, and female, intersex means a congenital condition.  Ts is transexual, Tg trans-gender, and Tv transvestite (A predominantly male fetish for female clothes.)

PEDO involves attraction to, and sex with children.  I throw in sex between children just out of literary laziness.  Adol, or Pube involves adolescents, or pubescence, PREG is youth at it's greatest extreme.

SOLO is usually mastrubation, or some other auto-erotic act.  Where no physical sex is involved it's typicly FANTasy, or marked NS.  JERK is non solo mastrubation, like circle jerks, and mutual mastrubation.

ORAL, and ANAL are pretty self explanitory.  Even if you aren't used to story codes, I trust you to figure them out for yourselves.  

ORGY is also pretty obvious, but I must clarify.  In my orgies, everyone is involved with everyone.  An MMF where the boys are so repressed that they can't bring themselves to look at, much less touch each other is a BANG, and will be so marked.  Also, I will mark MMF, FFM, MMM, FFF, and other threeways TROIs as in Menage'.

BUKKake comes from a Japanese fetish for drenching someone in semen.  Any story so marked will have multiple cumshots, probably with the same target, and quite possibly drinking/eating.

BDSM stands for Bondage, Domination/submission, and Sadism/masochism.  A catch-all for the whole spectrum of these fetishes, I will use BOND, Ds, and Sm where they are more appropriate.  FemD means a female in the dominant position, male dominant stories I'll leave unmarked because it's more socially acceptible (for some reason).  In most of these, it is consentual, at least to start.  

RAPE is another obvious one that I'll clarify.  I define it as sexual coition, or penetration without concent.  It applies equaly to forcably penetrating, or being forced to penetrate.  MOLLestation is sexual assault short of penetration,  FONDling is with hands, and FROTtage/teurism by rubbing the genitals against the victim, et cetera.  RELUctant means consentual, but under duress, COERcion means the concent was somehow forced.  Sexual SADEism is torture.

PARAphilia is a fetish that has escalated to the point where it interferes with normal sex.  A paraphile cannot become aroused, much less orgasm without the fixiation represented somehow, but may climax from it without any other stimulus.  

PICArism, a particular paraphilia focused on peircing flesh.  Picarists typically prefer women with large breasts, and may lean towards fat over thin because it means more flesh.

SciF marks stories with a future context, or higher than modern technology.  I write "Hard" science fiction, meaning the tech has to be possible, and believable.  I don't write magic in drag like transporter beams, or chemical potions that instantly turn men into women.

CYBR means Cybersex, usually involving a direct Mind-To-Mind interface so that both partners can feel each other's pleasures, and even build up to a feedback loop, which can get pretty intense.  (Heart attacks can happen if the limiters are disabled.)  May also mean a Cyber-fetishist, who is paraphilicly attracted to Robots, Cybernetic Implants, and Augmentation.

FUTA denotes Futanari, a particular Ecci involving Hermaphrodites.  My version are geneticly altered human women which retroacatively develop the Wolffian ducts into a penis, instead of a clitorus.  Ovarian Semi-hermaphrodites, they ejaculate eggs, and can't impregnate women, though the eggs can be fertilised in utero by a human male.

YIFF means Furry, or sex involving Hum/Animal hybrids.  Similar to the Futanari, they are geneticly engineered, but they cannot be retroactively created from an existing Karyotype.  In a nutshell, they are born that way, a Human can't become one.  YIPH involves a specific race of Feline hybrids, called the Yipheth, (The degeneration is because they can't pronounce "Yiphess.") AKA Mraui.

CHTUlhu means I've been reading Lovecraft again, and getting ideas, again.  Despite the name, I don't generally use the Mythos, or any other supernatural entities.  All the horrors are for the most part human (or used to be) instead of ancient alien gods from the Pliades.  I happen to think that makes them somehow even more horrifying.  In general, I go for the HORRor mood more than the alien bestiary.

Speaking of which, BESTiality means sex between species.  Should I write a dog rapes cat story (not likely) it will still be marked BEST.  Yiff is only sex with hybrids, or fetishizing hybrids (Some characters are insane enough to think they can interbreed with, or become another species, usually with Magical ideation.)  RACE marks stories involving interracial action, or fixation toward a certain descent.