See Daesh
Daesh – An Irhabi organization that broke with the al-Qaeda network and took control of large parts of Iraq and Syria, where in June 2014, it declared a caliphate, a traditional form of Islamic governance. By December 2017, US-led coalition forces and the Iraqi government had recaptured all territory under its control in Iraq. Daesh was largely made up of Irhabis from Iraq and Syria but had drawn Irhabis from across the world. The term Daesh is an Arabic acronym from “ad-Dawlah al-Islamiyah fi’l-Iraq wa-sh-Sham”, which translates as the ‘Islamic State in Iraq and Syria’ (ISIS), or ‘Islamic State in Iraq and the Levant’ (ISIL), whilst the group in June 2014, began to refer to itself as “ad-Dawlah al-Islamiyah” or Islamic State (IS).
The term ‘Islamic State’, IS, ISIS or ISIL, should not be used at all to describe the group, but rather Daesh at all times, in the same way that Al-Qaeda is not translated into its Arabic equivalent as ‘The Base’.
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Islamic State (IS)
Reuters: Reuters uses Islamic State on first reference and IS on second reference, and avoids ISIS and ISIL. Islamic State refers to the Islamic militant organization that broke with the al Qaeda network in 2013 and took control of large parts of Iraq and Syria, where in 2014 it declared a caliphate, a traditional form of Islamic rule. It is largely made up of Sunni militants from Iraq and Syria but has drawn jihadi fighters from across the Muslim world and Europe.
The group was originally known as Islamic State in Iraq and Syria (ISIS), or Islamic State in Iraq and the Levant (ISIL) and is sometimes also referred to by its Arabic acronym Da’ish or Daesh from “ad-Dawlah al-Islamiyah fi’l-Iraq wa-sh-Sham”, but on June 29, 2014 the group proclaimed itself a worldwide caliphate and renamed itself “ad-Dawlah al-Islamiyah” or Islamic State (IS).