Question: Which Irish symbol used in heraldry to denote the Irish province of Ulster is included in Flag of Ulster?

Context paragraphs:
Red Hand of Ulster: The Red Hand of Ulster () is an Irish symbol used in heraldry to denote the Irish province of Ulster.

Scotch-Irish Canadians: Scotch-Irish Canadians are those who are Ulster Scots or those who have Ulster Scots ancestry who live in or were born in Canada.  Ulster Scots are Lowland Scots and Northern English people who immigrated to the Irish Province of Ulster in 1690.  This was known as the Plantation of Ulster.

Flag of Ulster: The Flag of Ulster is a historic banner used to represent Ulster, one of the four provinces of Ireland.  The Red Hand of Ulster is a symbol that is either derived from the O'Neill dynasty, then the most prominent Irish clan in Ulster, or the Dextra Dei of early Christian iconography.  The gold background featuring a red cross comes from the coat of arms of the Burkes, a Hiberno-Norman noble family.

Ulster Rugby: Ulster Rugby (Irish: "Rugbaí Uladh" ) is one of the four professional provincial rugby teams from the island of Ireland.  They compete in the Pro14 and the European Rugby Champions Cup.  The team represents the Irish Rugby Football Union (IRFU) Ulster Branch, which is one of the four primary branches of the IRFU and is responsible for rugby union throughout the geographical Irish province of Ulster, comprising six counties in Northern Ireland and three counties in the Republic of Ireland.

Ulster Irish: Ulster Irish is the dialect of the Irish language spoken in the province of Ulster.  It "occupies a central position in the Gaelic world made up of Ireland, Scotland and the Isle of Man".  Ulster Irish thus has more in common with Scottish Gaelic and Manx than other Irish dialects do.  Within Ulster there have historically been two main sub-dialects: West Ulster Irish and East Ulster Irish.  The Western dialect is spoken in County Donegal and once was in parts of neighbouring counties, hence the name Donegal Irish.  The Eastern dialect was spoken in most of the rest of Ulster and northern parts of counties Louth and Meath.

Irish heraldry: Irish heraldry is the forms of heraldry, such as coats of arms, in Ireland.  Since 1 April 1943 it is regulated in the Republic of Ireland by the Office of the Chief Herald of Ireland and in Northern Ireland by Norroy and Ulster King of Arms.  Prior to that heraldry on the whole island of Ireland was a function of the Ulster King of Arms, a crown office dating from 1552.  Despite its name the Ulster King of Arms was based in Dublin.

Broad arrow: A broad arrow, of which a pheon is a variant, is a stylised representation of a metal arrowhead, comprising a tang and two barbs meeting at a point.  It is a symbol used traditionally in heraldry, most notably in England, and later by the British government to mark government property.  In heraldry, the arrowhead generally points downwards, whereas in other contexts it more usually points upwards.

Ulster Protestants: Ulster Protestants (Irish: "Protastúnaigh Uladh" ) are an ethnoreligious group in the Irish province of Ulster, where they make up about 43% of the population.  Many Ulster Protestants are descendants of the Protestant settlers involved in the early 17th century Ulster Plantation, which introduced the first significant numbers of Protestants into the west and centre of the province.  These settlers were mostly Lowland Scottish and Northern English people and predominantly from Galloway, the Scottish Borders and Northumberland.

Ulster Banner: The Ulster Banner (Ulster-Scots: "Ulstèr Bannèr"; Irish: "Meirge Uladh" ) is a heraldic banner taken from the former coat of arms of Northern Ireland, consisting of a red cross on a white field, upon which is a crowned six-pointed star with a red hand in the centre.  It was the flag of the former Government of Northern Ireland and common flag of Northern Ireland from 1953 until that government was abolished in 1972.  It was adopted to mark the coronation of Queen Elizabeth II, and was first flown over Parliament Buildings on 1 July 1953, in honour of the Queen's visit.  The Minister of Home Affairs announced that, while the Union Jack was the only standard officially recognised, those who wished to have a distinctive Ulster symbol might use the banner.  Since 1972, the Ulster Banner has had no official status and is not used by the current Northern Ireland government or by the British government.  However, the Ulster Banner is still in common use by loyalists/unionists, and to represent Northern Ireland internationally in some sporting competitions.  It has become a symbol of Ulster loyalism and is a contentious symbol.  In recent years there have been calls for a new, neutral flag for Northern Ireland to replace the Ulster Banner.

Service mark symbol: The service mark symbol (℠), the letters "SM" in superscript style) is a symbol used in the United States to provide notice that the preceding mark is a service mark.  This symbol has some legal force, and is typically used for service marks not yet registered with the U.S. Patent and Trademark Office; registered service marks are instead marked with the same symbol used for registered trademarks, the registered trademark symbol ®.  The proper manner to display the symbol is immediately following the mark in superscript style.

Supporting paragraphs: Flag of Ulster Red Hand of Ulster
Answer: The Red Hand of Ulster