Guest XxX, we are a moderated archive, and therefore we enforce the rules on required tags, etc. So, the moderators do make sure that stories are correctly tagged, and if they are not, the moderators ask the authors to fix the missing tags.
Since our mods are human (mostly ) there can always (on rare occasions) be mistakes, or missed tags that are not addressed. And if you find a story like that, it would be highly appreciated if you could let us know, and send us a link to the "offending" story.
To do that, you can either click the little "Report" button at the bottom of each chapter (this is the best option), send an email to: tos_team@adult-fanfiction.org or post a report here: http://www2.adult-fanfiction.org/forum/index.php/forum/97-all-other-tos-violations/ No matter which option you use, please be as detailed as you can, providing links to the story, name of the story, and what is missing.
Beyond that, I agree with CL, and suggest you keep your eyes open for the PWP-tag.
Thank you, and we hope you have fun.