Can a person's legal name be all lowercase or all capital letters or some strange mix, or are there restrictions about it? Or maybe capitalization is not even part of the name, it is just a part of grammar for proper nouns, with traditional/linguistic exceptions for names like "McDonald" or "von Neumann"?
(This is just a curiosity question so it doesn't matter to me which countries/states the answers are based on.)
Or maybe capitalization is not even part of the name
That's pretty much it. No court would fail to recognize the name "John Doe" in the string "JOHN DOE"; similarly, if someone established or claimed to establish their legal name as "john doe" then the only violations committed by someone writing it as "John Doe" or "JOHN DOE" would be violations of style, perhaps, or of etiquette.
Now, just in case this is related to the crackpot conspiracy theorists from the "sovereign citizen" or "freeman on the land" movements, a few words are in order. If you don't already know about this, you might find it interesting. In general, this is a school of thought that attempts to establish the illegitimacy of government authority by employing a number of illogical and willful misinterpretations of (often obsolete, foreign, or otherwise irrelevant) legal texts. Among these is the idea that the capitalization of a name is significant.
From Wikipedia's article on the sovereign citizen movement:
In a criminal case in 2013, the United States District Court for the Western District of Washington noted:
Defendant [Kenneth Wayne Leaming] is apparently a member of a group loosely styled "sovereign citizens". The Court has deduced this from a number of Defendant's peculiar habits.
First, like Mr. Leaming, sovereign citizens are fascinated by capitalization. They appear to believe that capitalizing names have some sort of legal effect. For example, Defendant writes that "the REGISTERED FACTS appearing in the above Paragraph evidence the uncontroverted and uncontrovertible FACTS that the SLAVERY SYSTEMS operated in the names UNITED STATES, United States, UNITED STATES OF AMERICA, and United States of America ... are terminated nunc pro tunc by public policy, U.C.C. 1-103 ..." (Def.'s Mandatory Jud. Not. at 2.) He appears to believe that by capitalizing "United States", he is referring to a different entity than the federal government. For better or for worse, it's the same country.
From its article on strawman theory:
One argument used by proponents of the strawman theory is based on a misinterpretation of the term capitis deminutio, used in ancient Roman law for the extinguishment of a person's former legal capacity. Adherents to the theory spell the term "Capitis Diminutio", and claim that capitis diminutio maxima (meaning, in Roman law, the loss of liberty, citizenship, and family) was represented by an individual's name being written in capital letters, hence the idea of individuals having a separate legal personality.
Proponents of the theory believe the evidence is found on the birth certificate itself. Because many certificates show all capitals to spell out a baby's name, JOHN DOE (under the Strawman theory) is the name of the "straw man", and John Doe is the baby's "real" name. As the child grows, most legal documents will contain capital letters, which means that his state-issued driver's license, his marriage license, his car registration, his criminal court records, his cable TV bill, correspondence from the IRS, etc., pertain to his strawman and not his sovereign identity.
(Note that there was no distinction between majuscule and minuscule letters in the Latin alphabet in ancient Roman times; this distinction arose in the 8th century, a few hundred years after the fall of the western empire.)
And finally, from Meads v. Meads, 2012 ABQB 571 (CanLII):
[323] Given the obsessive focus of the OPCA movement for documentary and procedural formalities (real or imagined), it is unsurprising that they have developed a wealth of arbitrary name-related rules. For example, Canadian courts have evaluated and rejected the following nomenclature-related schemes:
a person is not immune from court action if that person identifies himself by an entirely different name, for example, “Mythlim‑Axkw” instead of “Kazimierz Chester Crischuk”: R. v. Crischuk, 2010 BCSC 716 at paras. 31-32, affirmed 2010 BCCA 391, 2010 D.T.C. 5141; Shakes v. Canada (Public Safety and Emergency Preparedness), 2011 CanLII 60494 at para. 11 (I.R.B.); Services de financement TD inc. c. Michaud, 2011 QCCQ 14868 at para. 6;
structuring a name in the format of [Firstname]-[Middlename]: [Lastname], i.e. “David-Kevin: Lindsay”, does not mean one is a separate person from “David Kevin Lindsay”: R. v. Lindsay, 2006 BCCA 150 at para. 3, 265 D.L.R. (4th) 193; R. v. Lindsay, 2008 BCPC 203 at para. 7, [2009] 1 C.T.C 86, affirmed 2010 BCSC 831, [2010] 5 C.T.C. 174, affirmed 2011 BCCA 99, 302 B.C.A.C. 76, leave refused [2011] S.C.C.A. No. 265;
structuring a name in the format [Firstname] of the [family] of [Lastname], i.e. “John Donald of the family Sargent”, does not mean one is a separate person from “John Donald Sargent”: R. v. Sargent, 2004 ONCJ 356 at para. 29, [2005] 1 C.T.C. 448;
there is no legal distinction between a name in upper case and lower case letters, and a name all in capital letters: R. v. Linehan, 2000 ABQB 815 at para. 13, 276 A.R. 383; R. v. Loosdrecht, 2008 BCPC 400 at para. 36, [2009] 4 C.T.C. 49; R. v. Lemieux, 2007 SKPC 135 at paras. 45-46, [2008] 2 C.T.C. 291;
a claim that the person named in litigation is incorrectly identified by a “war name” or “nom de guerre” is irrelevant: Canada v. Galbraith, 2001 BCSC 675 at paras. 25-29, 54 W.C.B. (2d) 504; and
a name all in capitals is not a “legal fiction” and not different from “a flesh, blood and bone man”: Ontario (Director, Family Responsibility Office) v. Boyle, [2006] O.J. No. 2181 (QL) at paras. 3-5, 149 A.C.W.S. (3d) 127 (Ont. Sup. Ct. J.).
This depends on jurisdiction and the general answer is yes/no/both/either/it depends.
See this well-known essay about what is or isn't true about names in general: Falsehoods Programmers Believe about Names by Patrick McKenzie (and a number of other renditions of the same name...)
In very brief, it is not universally true that all persons have a name, or a single name, or a single canonical name, or a small set of canonical names (let alone unique, or adhering to any particular orthographic convention, or fixed over time).
Any name that is on a Japanese identity document (the "my Number" card/ID card) or in the official citizen register is written in Hiragana, Katakana or Kanji. None of these scripts support capitalization. Latin letters ("Romanji") do not appear on documents that are not international passports - where they only appear as a transliteration of the Japanese document entry. An exception to the no latin characters on internal documents are Residency cards for foreigners that do not have Japanese Citizenship, their cards contain the subject name, all in monospace capital letters. However, naturalization requires choosing a name that is written in Hiragana, Katakana, or Kanji (there's a list which are allowable).
Similarly, the Chinese script does not support capitalization either, nor does Hangul. In both Chinas and Koreas, you need the name to be in the respective script as a citizen.
As a result, Japan, the People's Republic of China, the Republic of China, The Republic of Korea, and the Democratic People's Republic of Korea all don't support a name in lowercase. Or uppercase for the matter, because all the letters are same sized.
Oh, and for the matter: the 5 are just the tip of the iceberg, and don't conform to the following programmer misconceptions on names...
- People’s names are written in ASCII. [ASCII is only Latin letters]
- People’s names are written in any single character set. [Japanese names can legally use all three!]
- People’s names are case sensitive.
- People’s names are case insensitive. [There is no case in those languages]
- People’s names are not written in ALL CAPS.
- People’s names are not written in all lower case letters. [Uh, there's no case?]
- People’s names have an order to them. Picking any ordering scheme will automatically result in consistent ordering among all systems, as long as both use the same ordering scheme for the same name. [So not true! If you transliterate to Latin characters, you also swap family names and given names around or not, depending on who is the recipient!]
- There exists an algorithm which transforms names and can be reversed losslessly. (Yes, yes, you can do it if your algorithm returns the input. You get a gold star.) [Try that with the almost 400 different names that contain Riku in Japanese, of which only few are duplicative, and all have different connotations and meanings]
In the U.S., names are generally left to the choice of parents and the person who bears the name, though as a convention of common languages spoken in the U.S., the name is likely to be given capital letters where appropriate. On some standardized forms, (I believe the SATs did this) names would be filled out in a field that was two rows with each column for one letter. The first row would have all the capital letters while the second row would use all lowercase letters. Leaving a column blank would indicate a space. So someone named McDonald would have the M and first instance of D in the upper column and all other letters in the lower column.
Other nations that are more controlling on legitimate names (not uncommon in nations with nearly homogenous ethnicities like Sweden) it's likely that the name will be properly capitalized in its acceptable spelling variants.
Usually, the signature is not about identity but acknowledging the document was accepted by leaving a unique mark on the document. Forgery detection relies on consistent characteristics of the signature (like how Walt Disney used the tail of the "y" in his name to underline the full signature) to determine authenticity. Someone who would always sign with all lower case letters is still valid because it creates a unique identity to the signature that a forger might not know (and it is impossible to make the same signature twice, so if the signer was not known to use an autopen, the signature may look too similar to be real.).
