In English, there are three types of compound words:
the closed form, in which the words are melded together, such as firefly, secondhand, softball, childlike, crosstown, redhead, keyboard, makeup, notebook;
the hyphenated form, such as daughter-in-law, master-at-arms, over-the-counter, six-pack, six-year-old, mass-produced;
and the open form, such ...
The correct spelling in this case is username.
The username is the (usually unique) thing you type in with your password, for example: bobsmith66.
The user name is the name of the user, the user's real life name, for example: Bob Smith. User name is sometimes used for username, but occasionally it makes a difference, so be clear and avoid the ambiguity. (...
For the compound noun front + end it is front end:
front end (plural front ends)
(computing) that part of a hardware or software system that is closest to the user.
frontend and front-end are alternative forms.
The compound noun front + end + engineering may be another matter.
"Frontend" and "backend" in this situation are technical terms, and as such I don't think they conform strictly to traditional ways of creating new words.
I'd put it in a similar category as putting the letter "e" in front of things: For example, should we call it e-mail and e-commerce or email and ecommerce? Most of us have settled on "email" but we split ...
The easiest thing to do, and the only way of being sure you agree with the authorities, is to look words up in the dictionary. Some of the hyphenations currently in American dictionaries make no sense at all. For example, the reason that prai-rie and fair-y are hyphenated the way they are seems to be that 150 years ago, the editors of Webster's dictionary ...
According to the Oxford English Dictionary, as quoted by the site below, you hyphenate if the compound adjective is before the noun and don't hyphenate if it is after the noun.
With compound adjectives formed from the adverb well and a participle (e.g., well-known), or from a phrase (e.g., up-to-date), you should use a hyphen (or hyphens) when the ...
All are acceptable, so you should follow your judgement.
British usage generally favours rather more hyphens than American usage; I'd use co-founder since cofounder doesn't look all that natural. I'd omit the hyphen in landowner, though, so it depends.
Longman and Collins tend to prefer unhyphenated while Chambers, predictably, insists on the hyphenated ...
The difference between "real time" and "real-time" is mostly a matter of style and placement. In most cases, there's no need to add the hyphen; "real time" will work very well. However, a case can be made for its use where it would clarify the writing. For example:
I am updating this in real time.
This is a real-time update.
In the second ...
According to Nick Marten's The Secret History of Typography in the Oxford English Dictionary, a colon followed by a dash is a typographical mark that the OED refers to as the dog's bollocks:
Citing usage from 1949, the OED calls this mark the dog’s bollocks, which it defines as, “typogr. a colon followed by a dash, regarded as forming a shape resembling ...
Yes, a two-word modifier (like this one) requires a hyphen, except that the commonly held convention is that adverbs ending in "ly" don't (like that one). See this table in the Chicago Manual of Style.
Burchfield's 1998 edition of Fowler's Modern English Usage says under hyphen, listing its uses:
6 To represent a common second element in all but the last word of a list, e.g. two-, three-, or four-fold.
This usage is perfectly acceptable; and in some cases it's really essential as Edwin Ashworth has commented:
We really have to prepare the ground- ...
BEFORE a noun, "almost-finished' is better, since it emphasizes that 'almost' is qualifying 'finished', not 'report'. Not important in this case, but compare 'longest living animal' with 'longest-living animal'.
As an addendum to Monica's fine answer, I'd like to add that there is a third possibility: fusing "non" with the word it precedes. A typical example would be "nonrelativistic", which seems to be Merriam-Webster's choice.
Similarly, one reads nonnegative, nonmagnetic, nonferrous, etc.
The Chicago Manual of Style advises:
When the second part of a hyphenated expression is omitted, the hyphen is retained, followed by a word space.
The hanging hyphen sets the reader up to expect a series of hyphenated expressions, all of which have the same second part. If you omit the hanging hyphen, therefore, it's not clear that the series has begun ...
According to this Google Ngram, both E-Commerce and E-commerce are valid and interchangeable:
Likewise, when not beginning a sentence (or in a headline, etc.), the term e-commerce is not capitalized:
(noun) commercial transactions conducted electronically on the Internet.
See what happens when e-commerce is added to the ...
The standard way to deal with this in English is your second example, "off- or on-topic". Another example of where the hyphen would be preserved for both forms of the hyphenated word might be pre- and post-, e.g.
The pre- and post-match responses of the soccer fans were markedly different.
The Chicago Manual of Style has these guidelines:
For compounds formed with fractions:
The noun form is open (a half hour)
The adjective form is hyphenated (a half-hour session)
For simple fractions:
Hyphenated in noun, adjective, and adverb forms, except when second element is already hyphenated (one-half; one and three-quarters;...
While I would say the third of your options, "non-defect-source-assesment processes", is most correct, I would strongly suggest trying to rephrase the subject for clarity. The hyphens can be used to indicate at what level the negation applies, so in this case "defect source assessment" is being negated, but "processes" is not. This is appropriate because you ...
"almost-finished" is a compound adjective. It is the correct way to say
"I am attaching an almost-finished version of the report".
"almost finished" is not correct in this case. Here's a sentence where you would use "almost finished" without the hyphen:
"I am almost finished with the work."
I (as a programmer and linguist) would pretty much always use runtime.
I think you might be building too much into the idea that runtime is an 'adjective' in compounds such as runtime environment. The word still remains more noun-like than adjective-like[*] in such cases and there's little motivation for inventing a special spelling in that case. And if you ...
It's (usually) intended as a form of light sarcasm or irony.
James P is saying that technically, if you take the official definition of a recession, squint hard and don't look too closely, you can say with a straight face that 2012 is not a recession year; however, everyone knows that regardless of what the official figures may say, 2012 really is a ...
Many writers would use a suspended hyphen.
Medium- to long-term.
You're allowed some discretion on this matter, as reputable writers are not entirely homogenous in their hyphen usage. Between the two that you suggested, the second seems to be more defensible. Writing "medium-to-long term" is probably not achieving what you're trying to achieve with the ...
According to Hyphenated Words: A Guide
You would not use a hyphen with the prefix non unless it is before a proper noun.
Do not hyphenate words prefixed by non, un, in, dis, co, anti, hyper, pre, re, post, out, bi, counter, de, semi, mis, mega, micro, inter, over, and under (among others).
Examples: nonaffiliated, nonemergency, uninfected, ...
One thing some style manuals suggest in this case is to use an en-dash rather than a hyphen. So
North America–based company
North America-based company.
The longer dash signals that it shouldn't be parsed as "America-based".
The Chicago Manual of Style notes:
With the exception of proper nouns (such as United States) and
compounds formed by an adverb ending in ly plus an adjective, it is
never incorrect to hyphenate adjectival compounds [of which
object-oriented is one] before a noun. When such compounds
follow the noun they modify, hyphenation is usually unnecessary,...