The second instance in which backbiting is permissible, which is the identifier, mentioning the evidence for this, and clarifying that what is mentioned in the hadith falls under this category.

The Shaykh : "And the identifier." This example is before us now, and there are many examples. The Messenger (peace be upon him) asked some of the Companions from Banu Salim: . They said: "Jud ibn Qays." He was asking them to identify him, so they answered by identifying him for him (peace be upon him), and they said: "On the condition that we disparage him."
And clearer than this example is when a woman came and two men had proposed to her. She came to the Prophet (peace and blessings be upon him) and said: O Messenger of Allah, so-and-so and so-and-so have proposed to me. He said: . She said: Abu Jahm. Abu Jahm is with a meem, not Abu Jahl with a lam. Abu Jahm was a man from the Companions, and Mu'awiyah ibn Abi Sufyan, each of them proposed to me. So it is as if she is saying: I am confused; should I agree to this one or that one? And it is as if she is saying to the Messenger (peace be upon him): Advise me, O Messenger of Allah, tell me: this one or that one? The Messenger (peace be upon him) did not say to her: take this one or take that one, because the matter is sensitive; because women’s tastes, objectives, and goals differ. So it was not for the Messenger (peace be upon him) to do anything other than describe each of the suitors to the woman being proposed to, describing each of them; therefore he (peace be upon him) said: . So we find here that the Messenger of Allah (peace and blessings be upon him) told us the fault of each of the suitors for that woman so that she would be fully informed. And the scholars mentioned in explaining the words of the Messenger (peace be upon him) regarding Abu Jahm and his statement about him that it is: , meaning that it signifies one of two things:
Either it is an allusion to the fact that he is known for his injustice toward women and his beating of them; because he does not put the stick down from his shoulder, an allusion to the fact that he is ready to beat the woman for the slightest sin, laziness, negligence, or the like.
And another meaning: it was said: that he is one who travels a lot; because it is the custom of the Arabs to put this stick and put... on the end of the stick, walking in these deserts. But the first meaning is the most correct, which became clear to the scholars.
So it means a poor man. And when we reflect on these two descriptions, we find that each of the two men would not be pleased to be mentioned by the Messenger (peace be upon him) specifically with what is in him. Abu Jahm does not want to be exposed before the women, especially before his prospective bride, that he is a man who beats women. And Mu'awiyah, likewise, it hurts him that it is said and the women know that he is a poor vagabond with no status or value in society; this is backbiting... but the benefit of advice, as he (peace be upon him) said in explaining the right of a Muslim upon a Muslim: . So if one comes and asks his neighbor or friend: What do you think of so-and-so? Good, if Allah wills? By Allah, I want to partner with him, and he knows that he is a traitor and that he is a deceiver and that he is such-and-such; he must mention what is in him; because this religion is advice. It is not said: this is backbiting; no, this is not from the forbidden backbiting. O so-and-so, what do you think of so-and-so? Good, if Allah wills? By Allah, he is a suitor from our side; likewise, you must clarify his faults so that if there is an agreement on the proposal, they are fully informed of the matter, not deceived... By Allah, backbiting is forbidden, but this description and identification, even if it includes backbiting, is not forbidden.
"Censure is not backbiting in six cases: *** the aggrieved and the identifier." This is the identifier.