What is the 'dhamma' category in 4sp satipatthana?

https://buddhism.stackexchange.com/questions/1313/what-is-the-meaning-of-dhamm%c4%81-in-the-context-of-the-four-satipa%e1%b9%ad%e1%b9%adh%c4%81na/34239#34239

Does anyone have a proper explanation as to why the fourth set is called "dhammas"?

Because the 4th category is not about dhamma (mental qualities or phenomena), it's ☸Dhamma-[teaching that leads directly to nirvana].

http://notesonthedhamma.blogspot.com/2019/07/proof-dharma-is-buddhas-teaching-not.html

The standard Theravada interpretation of the cryptic formula in 4sp satipatthana, is that one focuses on one of the frames to the exclusion of the other 3. But that's not the real purpose. The real meaning, is that one should see "body as body [as it actually is]".http://notesonthedhamma.blogspot.com/2019/05/the-real-meaning-of-cryptic-formula-in.html

For ☸Dhamma, the meaning of seeing ☸Dhamma as ☸Dhamma as it actually is, is very similar in meaning to  ☸Dhamma-anu-dhamma☸📐 {the practice of} dhamma/Dhamma that accords with {the Buddha's} ☸Dhamma. http://lucid24.org/tped/d/dhamma/index.html

EA, the MN 10  (satipatthana sutta) parallel in Chinese Agama, supports my interpretation

Or at the very least, has an idea much closer to mine, than to Theravada.
It looks like they're interpretation is that you take any dhamma [thing, quality, phenomena], and put it through a thorough ☸Dhamma investigation, after attaining 4 jhanas via 7sb.

4sp #4: dhamma anupassasna

“How does a monk in regard to dharmas contemplate the characteristics of dharmas as a satipaṭṭhāna? Here a monk cultivates the mindfulness awakening factor supported by insight, supported by dispassion, and supported by cessation, discarding evil states.

7sb are actively developed with STED 7sb formula, not passively examining presence and arising factors as in MN 10

“He cultivates the [investigation-of-]dharmas awakening factor [supported by insight, supported by dispassion, and supported by cessation, discarding evil states].
“He cultivates the energy awakening factor [supported by insight, supported by dispassion, and supported by cessation, discarding evil states].
“He cultivates the joy awakening factor [supported by insight, supported by dispassion, and supported by cessation, discarding evil states].14
“He cultivates the tranquillity awakening factor [supported by insight, supported by dispassion, and supported by cessation, discarding evil states].
“He cultivates the concentration awakening factor [supported by insight, supported by dispassion, and supported by cessation, discarding evil states].

「云何比 丘法法相觀意止？於是，比丘修念覺意，依 觀、依無欲、依滅盡，捨諸惡法。修法覺意、 修精進覺意、修念覺意、修猗覺意、修三昧 覺意、修護覺意，依觀、依無欲、依滅盡，捨 諸惡法。如是，比丘法法相觀意止。	“He cultivates the equanimity awakening factor supported by insight, supported by dispassion, and supported by cessation, discarding evil states. In this way a monk [in regard to] dharmas contemplates the characteristics of dharmas as a satipaṭṭhāna.

4 jhanas, are actively developed, as part of 4sp, not passively examined from outside as in DN 22

(1st jhāna)

「復次，比 丘！Fù cì, bǐqiū!	“Further more, Bhikkhus!
於愛欲解脫，Wū àiyù jiětuō,	free from craving for sensual pleasures,
除惡不-善法，Chú è bùshàn fǎ,	removing evil (and) un-wholesome dhamma [qualities],
有覺、有觀，Yǒu jué, yǒu guān,	with coarse-thinking (and) with subtle-thinking,
有猗念，Yǒu yī niàn,	with tranquility (and) mindfulness,
樂於初禪而自娛樂。Lèwū chū chán ér zì yúlè.	(he) delights in first Jhāna, and he experiences delight.

(jhāna is satipaṭṭhāna refrain)

如是，Rúshì,	In this way,
比丘 法 Bǐqiū fǎ	(a) Bhikkhu [in regard to] dhammas,
法相 fǎxiāng	(those) dhamma characteristics
觀意止。 Guān yì zhǐ.	(he) contemplates (as a) satipaṭṭhāna.

(A note on vitakka and vicāra)

_{Ven. Anālayo translated jue and guan as “directed awareness and sustained contemplation,” but that’s a translation based on an extrapolation of the literal reading of some archaic characters (in non-Buddhist Chinese contexts, they mean “realize” and “observe,” respectively). The Mahaprajnaparamita-sastra and the Yogacarabhumi (texts that are traditionally used as dictionaries), among others, explain that jue and guan should be understood as “coarse thinking” and “subtle thinking,” respectively.}

(2nd jhāna)

「復次，比 丘！Fù cì, bǐqiū!	“Further more, Bhikkhus!
捨有覺、有觀，Shě yǒu jué, yǒu guān,	discarding coarse-thinking (and) subtle-thinking,
內 發歡喜，Nèi fā huānxǐ,	Internally arousing joy
專其一意，Zhuān qí yīyì,	the mind being unified,
成無覺、無觀，Chéng wú jué, wú guān,	achieved no coarse-thinking (and) no subtle-thinking,
念猗 Niàn yī	mindful (and) tranquil,
喜安， xǐ'ān,	(with) joy (and) ease,
遊二禪而自娛樂。Yóu èr chán ér zì yúlè.	(he) travels-to second Jhāna and he-himself (experiences) happy pleasure [sukha].

(jhāna is satipaṭṭhāna refrain)

如是，Rúshì,	In this way,
比丘 法 Bǐqiū fǎ	(a) Bhikkhu [in regard to] dhammas,
法相 fǎxiāng	(those) dhamma characteristics
觀意止。 Guān yì zhǐ.	(he) contemplates (as a) satipaṭṭhāna.

(3rd jhāna)

「復次，比 丘！Fù cì, bǐqiū!	“Further more, Bhikkhus!
捨於念，Shě wū niàn,	discarding [joy] mindfully
修於護，xiū wū hù,	(he) cultivates equanimity in this respect,
恒自覺知 身覺樂，héng zìjué zhī shēn jué lè,	constantly he experiences (and) knows (with his) body the-experience-of pleasure [sukha].
諸賢聖所求，zhūxián shèng suǒ qiú,	as sought after by noble ones,
護念清淨，hù niàn qīngjìng,	equanimity (and) mindfulness, (are) pure-(and)-clean,
行於三 禪。xíng wū sān chán.	(he) engages in third Jhāna.

(jhāna is satipaṭṭhāna refrain)

如是，Rúshì,	In this way,
比丘 法 Bǐqiū fǎ	(a) Bhikkhu [in regard to] dhammas,
法相 fǎxiāng	(those) dhamma characteristics
觀意止。 Guān yì zhǐ.	(he) contemplates (as a) satipaṭṭhāna.

(4th jhāna)

「復次，比 丘！Fù cì, bǐqiū!	“Further more, Bhikkhus!
捨 苦樂心，Shě kǔ lè xīn,	discarding pain [dukkha] (and) pleasure [sukha] (of) heart/mind,
無復憂喜，wú fù yōu xǐ,	without sadness (and) joy,
無苦無樂，wú kǔ wú lè,	without pain [dukkha] (and) without pleasure [sukha],
護念清淨，hù niàn qīngjìng,	equanimity (and) mindfulness, (are) pure-(and)-clean,
樂 於四禪。lèwū sì chán.	(He) delights in fourth Jhāna.

(jhāna is satipaṭṭhāna refrain)

如是，Rúshì,	In this way,
比丘 法 Bǐqiū fǎ	(a) Bhikkhu [in regard to] dhammas,
法相 fǎxiāng	(those) dhamma characteristics
觀意止。 Guān yì zhǐ.	(he) contemplates (as a) satipaṭṭhāna.

(arising, ceasing, pari-mukhaṃ refrain)

彼行習 法，Bǐ xíng xí fǎ,	“he practices the venue to [its] origination,
行盡法，Xíng jǐn fǎ,	he practices the venue to [its] cessation,
并行習盡之法 Bìngxíng xí jǐn zhī fǎ	and he practices the venue to both [its] origination and cessation.”
而自娛樂， ér zì yúlè,	experiencing joy in himself [by removing evil thoughts and being free from worry and sorrow].
便 得法意止 Biàn défǎ yì zhǐ	He gains the satipaṭṭhāna of dharmas
而現在前。 ér xiànzài qián. (pari-mukha)	and keeps it present in front [of himself].

(A note on pari-mukha)

_{Visuddhimagga apologists often explain the parimukha-instruction as “bringing attentional focus” to one’s nose-tip. But Chinese passages where that instruction occur actually are virtually identical to what you find here in EA. Here in EA, the expression clearly means something to the effect of “keeping it present,” as a nose-tip focus would not be a sensible starting point for dharma-based satipatthana. If it means “keeping it present” here, why would it mean “fixing on nose-tip” elsewhere?}

(EA 12.1 translation notes for STED 4 jhānas and 4sp)

_{護 is equanimity. This is peculiar to this EA recension.
捨 (Shě) is what most Chinese Agamas have for equanimity.
樂 as sukha is a noun sometimes, but also gets used as a verb "to enjoy" or "to delight in". (such as in 4th jhāna)
意止 (yì zhǐ) in EA is satipaṭṭhāna.
念住 (nianzhu) is the phrase for satipaṭṭhāna used in most Chinese agamas.}

(Not in the Pāli! Taking dhamma anupassana all the way to Nirvana)

可知可見，除去亂想， 無所依猗，不起世間想；已不起想，便無 畏怖；已無畏怖，生死便盡；梵行已立，所作 已辦，更不復受有，如實知之。

“He is able to know, able to see, discarding distracted perceptions, he does not depend on anything and does not give rise to worldly perceptions. Not having given rise to such perceptions he is not agitated, not being agitated he knows as it really is that ‘birth and death have been extinguished, the holy life has been established, what had to be done has been done, there is no more experiencing of [another] existence.’

Response to Questions and Commenters

on the interpretation of analyzing dhamma-phenomena through Dhamma-teaching framework

my response to one of the comments below: in DN 22 though, the 4 noble truths and noble eightfold path description under Dhammaanupassana are just cut and paste jobs from other fundamental suttas defining what those factors are. Unlike the EA parallel where Dhamma anupassana is described where you're activing USING a Dhamma-teaching framework to analyze the phenomena. DN 22 maybe implies that, but the Theravada model is so massive and convoluted you can't tell for sure. In EA, for sure that's what they're doing. The problem is if you take DN 22 as viewing dhamma-phenomena viewed through Dhamma-teaching framework, then how do you approach the other 3 satipatthana where that wouldn't work? It doesn't say kaya-Dhamma-anupassi, vedana-dhamma-anupassa, etc...