significance or meaning of the word in medieval Occitania.

"Paratge" translates literally into English as peerage, but this gives almost no clue to the significance or meaning of the word in medieval Occitania.
Paratge denoted a whole world-view, almost a philosophy, as alien to the modern mind as it was to the medieval French Crusaders. The word meant something more than honour, courtesy, nobility, chivalry or gentility though our concepts of honour, courtesy, nobility, chivalry and gentility all owe something to the concept of "paratge". 
The word also carried implications of balance, natural order, and what is right. Paratge does not seem to have been a distinctly Cathar notion. The Count of Toulouse could reportedly use the word to the Pope in reminding him of his duty to paratge. In any case we have no indication of any disagreement between the two belief systems, which appear to have coexisted in complete harmony. If it seems odd that we have even the faintest echo of the concept in English, it is well to remember that Occitan was the first language of many in England, including two queens (Eleanor of Aquitaine, and John's wife Isobel) and an English King, Richard I).

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The nearest concept to paratge we know of elsewhere seems to be the ancient Egyptian idea of Ma'aht - another untranslatable word carrying suggestions of right, cosmic balance and natural order to which may be added ideas of contentment, joy and light. (Ma'aht was embodied as a goddess, and played a part in the development of Christian concepts of heaven and hell). The ancient Greeks seem to have had a similar idea. The word kosmos, the origin of our word cosmos, meant not just the universe but a state of universal order and harmony. Plato, in Meno, (apparently referring specifically to the Pythagoreans) says "The wise men tell us that heaven and earth, and gods and men, are bound together by kinship, love, orderliness, temperance and justice; and for this reason my friend they give to the whole the name kosmos, not a name implying disorder or licenciousness". In the modern world, the nearest we can come to it is probably in Eastern philosophies: the yin-yang and the Buddhist ideas of karma and what is "right".
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The word paratge was used extensively in Occitan writings, and it features heavily in the works of troubadours and especially in the Song of the Cathar Wars. If you knew that a man upheld paratge, then that was pretty much all you needed to know about him. Similarly, if you knew that he despised paratge then again that was all you needed to know.
In the latter part of the Canso (The Song of the Cathar Wars)  written in Occitan the writer is horrified and mystified that the French invaders seem to have no respect for paratge, or even any understanding of it. The charge is more serious than any other - indeed it probably encompasses all the others - deceit, brutality, vandalism, lying, hypocrisy, even mass-murder. Here is an observation, laisse 137, referring to the French Catholic Crusader victory over the joint forces of King Pedro II of Aragon and Count Raymond VI of Toulouse defending their lands at Muret:
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Toto lo mons ne valg mens, de ver o sapiatz, Car Paratges NE fo destruitz e decassatz E totz Crestianesmes aonitz abassatz.

It diminished the whole world, be sure of that, For it destroyed and drove out paratge, It disgraced and shamed all Christendom.

Here is a later example from a famous coruscating indictment of a dead crusade leader, Simon de Montfort, refering to the epitaph on his original tomb at the Cathedral of Saint-Nazaire in Carcassonne. The inscription on it is now lost, but we know that it envisaged Simon as a saint enthroned in heaven, enjoying God's reward for his earthly deeds:

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Context Occitan Text English Translation
Laisse 151. Raymond VI, Count of Toulouse rails at Pope Innocent III for thinking to dispossess the count's son of his inheritance. E l'efans, que no sab ni falhir ni pecar, Mandas sa terra toldre e lo vols decassar! E tu, que deus Paratge e Merce guovernar, Membre•t Dieus e Paratges e no•m laiches pecar ...And the boy, not capable of doing wrong: you order his fiefs to be taken from him and for him to be driven out! You who should rule by mercy and paratge! Be mindful of paratge and of God!
Laisse 154. Guy of Cavillon gives advice to the young Raymond future Raymond VII, outlining his duty to paratge. ... lo coms de Montfort que destrui Los baros e la gleiza de Roma e la prezicacios fa estar tot Paratge aunit e vergonhos, qu'en aisi Es Paratges tornatz de sus en jos; que si per vos no•s leva per totz tems Es rescos. E si Pretz e Paratges no•s restaura per vos, doncs Es lo mortz Paratges e totz lo mons en vos. E pus de tot Paratge etz vera sospeisos, o totz, Paratges moria o vos que siatz pros! ...the count of Montfort who destroys men, he and the Church at Rome and the preachers are covering paratge with shame. They have cast it down from its high place, and if you do not raise it up, it will vanish for ever. If worth and paratge do not rise again through you, then paratge will die - with it the whole world will die. You are the true hope of all paratge and the choice is yours: either you show valour, or paratge dies!
Laisse 137 and Laisse 141: On the defeat of King Peter II of Aragon and Raymond VI of Toulouse at the battle of Muret in 1213
Totz lo mons NE valg mens, de ver o sapiatz, car Paratges NE FO destruitz e decassatz. E totz Crestianesmes aonitz e abassatz.
... A tot Crestianesme et a trastotas gens

It diminished the whole world, be sure of that, for it destroyed and drove out paratge. It disgraced and shamed all Christendom.
...It dishonoured the whole of Christendom and all humanity.
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The concept of paratge is still known and respected in the Languedoc. On the eight hundredth anniversary of the massacre of Cathars by French Catholic crusaders at Minerve on 22 July 1210, the inhabitants of the town installed a memorial to their ancestors - shown below. It says, in Occitan: "Minerve remembers PARATGE!"

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An Excursus
In many respects an upholder of paratge resembled a perfect knight and an ideal gentleman. King Richard I of England was familiar with the concept - he was from the Aquitaine himself, the son of Eleanor of Aquitaine and the great grandson of William IX the first troubadour. He was a fluent speaker of Occitan and must certainly have understood and respected paratge. He himself was a troubadour and was greatly esteemed in his time. Even his Moslem enemies called him Melek Ric - the True King.
Yet Richard was not the greatest embodiment of the ideal of Paratge. The two men remembered by English history who perhaps most embodied the ideals of paratge were both alive at the same time as Richard, and both knew him. One was William Marshall. The other was Al-Malik al-Nasir Saleh ed-Din Yusuf, better known to us as Saladin. Both were also renowned and honoured even by their enemies. Richard held them both in the very highest esteem - though he spent years fighting Saladin, and had once had to beg for quarter from William Marshall. History gives us a good indication of both men:
Saladin - Salah al-Dunya al-Din. On one famous occasion, seeing Richard's horse killed beneath him in battle, Saladin sent him another. We also know that Richard offered the hand of his sister in marriage to Saladin's brother. Such was Saladin's reputation that it was widely believed in the West that Saladin had been knighted by Richard, possibly a distorted version of an actual event as Richard had knighted Saladin's nephew. When Muslim raiders took a baby from its Christian mother, she sought out Saladin and appealed to him in person. Moved to tears he had the infant found and returned to her. When one of his dared to bring a legal actuion against him, he left his throne and submitted to trial like anyone else. When he won the case he liberally rewarded his opponent. When he took Jerusalem he forgave Balian of Ibelin who had led the defence, despite having taking an oath not to do so (he had been released on this condition). While the crusaders had slaughtered almost the whole population when they had taken Jerusalem in 1099, Saladin killed not a single citizen when he took it in 1187.
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Richard the Lion Heart
King of England




Richard Iᵉʳ of England said Lion Heart was King of England, Duke of Normandy, Duke of Aquitaine, count of Poitiers, Count of Maine and Count of Anjou 1189 until his death in 1199. He was also a patron of troubadours and wrote poetry. Wikipédia

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http://www.midi-france.info/190403_paratge.htm