WhAt iS tHiS kINd oF caPiTaLiSAtIOn cAlLeD? - random capitalisation or intermittent capitalisation

After digging for a long time, I finally discovered the name of this kind of capitalisation. It's called studly caps or sometimes sticky caps.

Studly caps:

Studly caps is a form of text notation in which the capitalization of letters varies by some pattern, or arbitrarily (usually also omitting spaces between words and often omitting some letters), for example, StUdLyCaPs, STuDLyCaPS or sTuDLycApS. Such patterns are identified by many users, ambiguously, as camel case. The typical alternative is to just replace spaces with underscores (as in snake case).

History:

According to the Jargon File, the origin and significance of the practice is obscure. Arbitrary variation found popularity among adolescent users during the BBS and early WWW eras of online culture, as if in parody of the marginally less idiosyncratic capitalization found in common trade and service marks of the time. Programming style guides, meanwhile, began to codify common StudlyCaps patterns for computer programmer populations, who are constrained by rules on the placement of whitespace that are incompatible with natural-language usage.

Unlike the use of all-lowercase letters, which suggests efficiency as a motivation, StudlyCaps requires additional effort to type (and read), either holding and releasing the shift key with one hand while hunting-and-pecking, or intermittently pressing one shift key or the other while touch typing.

This method (without actually named "studly caps" or else) was extensively used since the 1980s in the BBS-world and warez scene (for example in FILE_ID.DIZ and .nfo files) to show "elite" (or elitist) attitude, the often used variant was using small-caps vowels and capitalised consonants (THiS iS aN eXCePTioNaLLy eLiTe SeNTeNCe.) or reversed capitals (eXTENDED kEY gNERERATOR pRO). The iNiQUiTY BBS software based on Renegade had a feature to support two variants of this automatically: either all vowels would be uppercase or all vowels would be lowercase, with the consonants as the other case.

Messages may be hidden in the capital and lower-case letters such as "ShoEboX" which spells "SEX" in capitals and "hobo" in lower-case. The webmail service Hotmail was originally stylized as HoTMaiL, which spells HTML in upper-case.

A meme in early 2017 called "Mocking Spongebob" used studly case to convey a mocking tone.

Studly caps is commonly used in social media sites such as Facebook, Twitter, Instagram and in chatting platforms such as Discord, WeChat and WhatsApp etc.

— Wikipedia

There's also a site that generates Studly caps online.

Toolpage — Studly caps generator

Results from Toolpage:

• stAcK ExchANgE
• ranDOm inTErMiTteNT caPItALiSAtIOn
• HeLlo. how ArE you dOing?

When used in the context of memes, you can refer to it as Spongebob case.

See for example:

• SpongeBob case — Jo Lokito's blog

• SpongeBob case — GitHub

• Rdrr.io — SpongeBob

One name for this case is alternating case. A text converter that uses the form (Alternating Case Converter) explains:

The alternating case converter converts text, so as a result the initial letter is a capital one and from there on the cases alternate between uppercase and lowercase. For this, a text needs to be entered into the form. Alternating case writing is particularly common on the Internet and is used by those who think it looks "cool". It is also known as Alternating Caps and Troutspeak.

Other converters (like this and this) also call it alternating case.

This usage is also attested in published work on typography and reading. Mary C. Dyson and Ching Yee Suen in Digital Fonts and Reading (2016) describe a study that assessed reader eye movement when reading alternating case.

McConkie and Zola [1979] presented passages of text in aLtErNaTiNg CaSe then on specific saccades the case alternation was switched (AlTeRnAtInG cAsE). The astonishing finding was that fixations following a case switch were no longer than fixations that did not follow a switch. [...] However, as you might guess, reading alternating case is more effortful than reading all lower case or all uppercase text [Rayner, McConkie, and Zola, 1980; Juhasz, Liversedge, White, and Rayner, 2006; Reingold, Yang, and Rayner, 2010]. It may be that alternating case disrupts normal word identification processes [Coltheart and Freeman, 1974] [... ]

These sources cited by Dyson and Suen show that scholarship in the mid-1970s was already using the term "alternating case." Here is the first study mentioned from 1979, McConkie, George W., and David Zola. "Is visual information integrated across successive fixations in reading?." Perception & psychophysics 25.3 (1979): 221-224, from the abstract:

College students read a passage presented in AlTeRnAtInG cAsE on a CRT while their eye movements were monitored. During certain saccades, the case of every letter was changed (a became A, B became b). This change was not perceived and had no effect on eye movements. Apparently visual features of the type which specify the difference between upper- and lowercase letters are not integrated across fixations during reading.

And here is the earliest study mentioned, Coltheart, Max, and Roger Freeman. "Case alternation impairs word identification." Bulletin of the Psychonomic Society 3.2 (1974): 102-104:

The prose passage was on the left page of a booklet, in upper case, lower case, or alternating case.

This experiment, then, has shown that the alternating-case condition does, in fact, lead to impaired word identification, even when character size is the same for upper- and lowercase characters.

So alternating case specifically describes the case of switching case with each letter, whereas words like studly case more generally describe the introduction of case internal to words or without spaces through a predictable pattern.