Hangul	McR	Yale	USG	ROK	DPRK	ISO/TR11941
ㄱ	k	k	k	g, k	k	k/g
ㄲ	kk	kk	kk	kk	kk	kk/gg
ㄴ	n	n	n	n	n	n
ㄷ	t	t	t	d, t	t	t/d
ㄸ	tt	tt	tt	tt	tt	tt/dd
ㄹ	r, n, l	l	r, l	r, l	r	l, r
ㅁ	m	m	m	m	m	m
ㅂ	p	p	p	b, p	p	p/b
ㅃ	pp	pp	pp	pp	pp	pp/bb
ㅅ	s	s	s	s	s	s
ㅆ	ss	ss	ss	ss	ss	ss
ㅇ	- ,ng	- ,ng	- ,ng	- ,ng	- ,ng	‘, - ,ng
ㅈ	ch	c	ch	j	j	c/j
ㅉ	tch	cc	tch	jj	jj	cc/jj
ㅊ	ch’	ch	ch’	ch	ch	ch/c
ㅋ	k’	kh	k’	k	kh	kh/k
ㅌ	t’	th	t’	t	th	th/t
ㅍ	p’	ph	p’	p	ph	ph/p
ㅎ	h	h	h	h	h	h
ㅏ	a	a	a	a	a	a
ㅑ	ya	ya	ya	ya	ya	ya
ㅓ	ŏ	e	o’	eo	ŏ	eo
ㅕ	yŏ	ye	yo’	yeo	yŏ	yeo
ㅗ	o	o	o	o	o	o
ㅛ	yo	yo	yo	yo	yo	yo
ㅜ	u	wu	u	u	u	u
ㅠ	yu	ywu	yu	yu	yu	yu
ㅡ	ŭ	u	u’	eu	ŭ	eu
ㅣ	i	i	i	i	i	i
ㅐ	ae	ay	ae	ae	ae	ae
ㅒ	yae	yay	yae	yae	yae	yae
ㅔ	e	ey	e	e	e	e
ㅖ	ye	yey	ye	ye	ye	ye
ㅘ	wa	wa	wa	wa	wa	wa
ㅙ	wae	way	wae	wae	wae	wae
ㅚ	oe	oy	oe	oe	oe	oe
ㅝ	wŏ	we	wo’	wo	wŏ	weo
ㅞ	we	wey	we	we	we	we
ㅟ	wi	wuy	wi	wi	wi	wi
ㅢ	ŭi	uy	u’i	ui	ŭi	yi

The table above details six systems for Romanizing or transliterating the Korean alphabet, including;

1. McCune-Reischauer (1937). Often abbreviated as “McR” or “MR,” this was the earliest Romanization system to gain widespread usage and is still the standard for Western academia other than linguistics. However the South Korean system has been replaced McR in most popular media since 2000. The most common problem with McR is the use of special characters that do not exist on the average keyboard (e.g., “ㅓ” as “ ŏ ”).
2. Yale (1942). This system is used primarily among academic linguists.
3. The U.S. government system (2005?). This system was devised for use by the Foreign Broadcast Information Service (FBIS), which translates and disseminates non-U.S. media within the government. While this system appears to have many similarities to McR, very little information is publicly available on this Romanization system.
4. The South Korean government system, also known as the Revised Romanization of Korean (RR), the Ministry of Culture (MC), or Ministry of Culture and Tourism (MCT) (2000). The South Korean government devised this system with little input from foreigners, and despite its inferiority in faithfully reproducing Korean sounds in the Roman alphabet, it has gained “nearly-universal” usage in South Korea since its introduction in 2000.
5. The North Korean government system (조선민주주의인민공화국 과학원) (1992, revised 2002).
6. ISO/TR11941 (1996). This was a failed attempt by North and South Korea to jointly devise a Romanization system. It was heavily based on the Yale system, but ultimately is incomplete. There is a chance of encountering this ISO in UN documents.

The table was populated with information from:

• Report on the Current Status of United Nations Romanization Systems for Geographic Names, Version 2.2, January 2003 (PDF)
• Korean Romanization (Wikipedia)
• FYI: FBIS To Modify DPRK, ROK Source Names (FAS)
• Hangul Romanizations (sori.org)

Notes:

• When more than one option is presented (e.g., “r, l” or “g, k”), the first represents the initial position, while the second is the final position. In the case of “ㅇ” the first position is silent and is represented by a “-” (dash).
• Most readers of this blog will primarily encounter RR, followed by McR, and perhaps the U.S. or DPRK systems depending on the websites you visit. Probably few will encounter much of the Yale or ISO systems.
• Lukoff Romanization and SKATS (Korean Morse equivalents) were not covered due to their near complete obsolescence.
• Information on the new U.S. government system is limited. The Romanization presented for this system is derived from the FAS report on FBIS. For double consonants it was a process of elimination (e.g., since “k’ ” is reserved for “ㅋ”, it is not reserved for “ㄲ”, etc.), and I had to take a best guess on the transliteration of Ssang-jieut (ㅉ) as “tch”, since the system seems to follow McR closely . If you can provide any additional information on this system, please leave a comment or contact me with this form.