I keep seeing roshei teivos on the site and, being comparatively uneducated, can't make heads or tails of most of them.
For example, one that I have seen on this site is "PTIJ" (which I assume refers to פתא"י or the like in Hebrew).
There is always a lot of discussion going on about what PTIJ doesn't mean, but no one has said what it does. Since this is a Torah site, I assume it refers to a concept in Torah. So I ask: to what Torah event or concept does פתא"י refer?
The roshei teivos פתא"י stand for פירושי תלמוד ארץ ישראל which means explanations of the Palestinian Talmud. The Palestinian Talmud is much more cryptic than the Babylonian Talmud, and as such requires extensive explanations for almost every line. This is why you often find people discussing whether a post fulfills the criteria of PTIJ/פתא"י – most of these posts are themselves rather cryptic, and it doesn't do anyone any good to explain cryptic passages by substituting it for something else cryptic. As Rambam writes in his introduction to Guide for the Perplexed:
For I observed that by expounding these passages by means of allegorical and mystical terms, we do not explain anything, but merely substitute one thing for another of the same nature.
תלמוד פרסי אין יעקב (Persian Talmud Isn't Jacob) is a collection of the stories and moral teachings of the Persian Talmud. The Persian Talmud, which predates both other Talmuds, comes from the days of Mordechai and Esther.
The Isn't Jacob's own commentary is called עקוב יעקב (Certainly Deceitful), or הכוזב for short. The foremost later commentary is called הסותר (The Contradictor). With commentaries such as these, you can understand why people prefer to discuss what PTIJ isn't rather than what it is.
PTIJ is actually the translation of ’פתי ג, where the J is commonly a Gimmel with a shtrichel. The word פתי means fool, and so the designation is that this question is for fools on the third level down.
This is not Rashei Tevot at all. It's a Hebrew transliteration of the (somewhat) English word "Ptui" which is defined as the sound made when spitting.
The reason that you tend to see this transliteration on this site close to Purim time is because these types of questions are not true Torah but humorous "quips" about Torah ideas. But, we get a lot of these types of questions, and too much laughter and frivolity accustom people towards ערוה (lewdness). (Pirkei Avot 3:17). Thus, devoutly religious and careful people may be tempted to spit when reading or hearing some of these questions, esp. if they have been reading too many in one day.
The rashe teivos פתא"י stand for פתי יאמין, a shorthand reference to this verse.
פתחי תשובה ארץ ישראל
Summary of answers regarding Eretz Yisrael
We are in the middle of a major machlokes whether the questions must involve problems occurring in Eretz Yisrael or if the people who answer the questions must be in Eretz Yisrael at the time in order to have the z'chus of siyata dishmaya (help from heaven). As a result we see discussions as to whether or not a question or answer applies.
