According to Sunni İslam Taqiyya is the allowance given to an individual to lie about himself (about his faith) if his life is in danger if he doesn't.
According to Shia İslam it means lying about the faith to propagate it.
90%+ Muslims are Sunni which means they share the same aqidah or beliefs but differ in jurisprudence.
You left off the other reasons. Like lying to those who not muslim in order to gain ones end.
For those interested, see this:
Taqiyya (lit. ‘caution’) denotes the deceit or dissimulation used by Shiites, who may lie and even commit blasphemous acts to conceal their religion when they are under threat of persecution from majority Sunnis. It has long been used in its other manifestation, as an integral part of Muslim military strategy, employing trickery and deceit to mislead the enemy (for a detailed discussion see John Esposito’s The Oxford Dictionary of Islam, Oxford University Press, 2003).
The Qur’an in a variety of verses (2:225, 3:28, 3:54, 9:3, 16:106, 40:28, and 66:2) establishes the religious legitimacy of breaking oaths, lying, unilaterally violating treaties, and generally scheming against non-Muslims. Allah Himself is described as “the best of schemers” (3:54, 8:30, 10:21), and Muhammad declared, as a justification for murdering unarmed prisoners after offering them safe passage, “war is deceit” (see the Hadith collection of Bukhari, vol. 4, book 52, nos. 268-271).
Example: So during the negotiations of Oslo I and II, Arafat’s willingness to acquiesce to Israeli demands was merely his acting as a good Muslim warrior, using taqiyya, deceit in warfare, to put his enemy at a disadvantage.
http://sheikyermami.com/taqiyya-holy-deception-quran-532/
Verses on this:
The Qur'an:
Qur'an (16:106) - Establishes that there are circumstances that can "compel" a Muslim to tell a lie.
Qur'an (3:28) - This verse tells Muslims not to take those outside the faith as friends, unless it is to "guard themselves."
Qur'an (9:3) - "...Allah and His Messenger are free from liability to the idolaters..." The dissolution of oaths with the pagans who remained at Mecca following its capture. They did nothing wrong, but were evicted anyway.
Qur'an (40:28) - A man is introduced as a believer, but one who must "hide his faith" among those who are not believers.
Qur'an (2:225) - "Allah will not call you to account for thoughtlessness in your oaths, but for the intention in your hearts" The context of this remark is marriage, which explains why Sharia allows spouses to lie to each other for the greater good.
Qur'an (66:2) - "Allah has already ordained for you, (O men), the dissolution of your oaths"
Qur'an (3:54) - "And they (the disbelievers) schemed, and Allah schemed (against them): and Allah is the best of schemers." The Arabic word used here for scheme (or plot) is makara, which literally means 'deceit'. If Allah is supremely deceitful toward unbelievers, then there is little basis for denying that Muslims are allowed to do the same. (See also 8:30 and 10:21)
From the Hadith:
Bukhari (52:269) - "The Prophet said, 'War is deceit.'" The context of this is thought to be the murder of Usayr ibn Zarim and his thirty unarmed men by Muhammad's men after he "guaranteed" them safe passage (see Additional Notes below).
Bukhari (49:857) - "He who makes peace between the people by inventing good information or saying good things, is not a liar." Lying is permitted when the end justifies the means.
Bukhari (84:64-65) - Speaking from a position of power at the time, Ali confirms that lying is permissible in order to deceive an "enemy."
Muslim (32:6303) - "...he did not hear that exemption was granted in anything what the people speak as lie but in three cases: in battle, for bringing reconciliation amongst persons and the narration of the words of the husband to his wife, and the narration of the words of a wife to her husband (in a twisted form in order to bring reconciliation between them)."
Bukhari (50:369) - Recounts the murder of a poet, Ka'b bin al-Ashraf, at Muhammad's insistence. The men who volunteered for the assassination used dishonesty to gain Ka'b's trust, pretending that they had turned against Muhammad. This drew the victim out of his fortress, whereupon he was brutally slaughtered despite putting up a ferocious struggle for his life.
Islamists interpret their scripture to say that they are allowed to lie about the nature of Islam in order to further their political goals.
Islamists also interpret taqiyya to permit lying about the nature of Islam to non-Muslims in order to convert them to Islam
Is that what you are doing here?