Title case rules in English vary wildly and can be roughly divided in to the eight categories following.

1. ALL CAPS

   THE WATER DAMAGE IS IN HER FAUX-ARMENIAN CATHEDRAL WING

2. Initial caps for everything

   The Water Damage Is In Her Faux-Armenian Cathedral Wing

3. Initial caps for everything, except non-initial articles, prepositions and conjunctions

   The Water Damage Is in Her Faux-Armenian Cathedral Wing

4. Initial caps for everything, except non-initial articles; prepositions; conjunctions & ‘to be’ forms

   The Water Damage is in Her Faux-Armenian Cathedral Wing

5. Initial caps for everything, except non-initial closed-class¹

   The Water Damage is in her Faux-Armenian Cathedral Wing

6. Initial caps for nouns and the 1st word

   The Water Damage is in her faux-Armenian Cathedral Wing

7. Standard sentence case (ie first word takes an initial cap as do proper nouns)

   The water damage is in her faux-Armenian cathedral wing

8. all lowercase

   the water damage is in her faux-armenian cathedral wing

Of these eight, numbers five and seven are the most common. Very roughly speaking, style five is US editorial practice and style seven is Commonwealth editorial practice.

It gets complicated, however. Even in places where style five above is the rule, long closed-class¹ words (eg ‘between’) sometimes taking an initial cap. The New York Times uses a five with occasional long closed-class exceptions style, for example.

And there are numerous UK publishers using style five (especially with the long closed-class words are a further exception variation) and numerous US publishers using style seven.

Also, scientific publishers, regardless of where they are, tend to stick with style seven (sentence case).

ALL CAPS is generally a sign of very good or very poor typesetting and design, mostly the latter. It takes a real eye for type and presentation to make ALL CAPS titles work. If you are doing your own typesetting and layout, and have that hard-earned designer’s eye, have at it. If you don’t have that designer’s eye, don’t tempt fate.

This is equally true for all lowercase titles.

Initial Caps For Everything (two above) is mostly a sign of typesetter uncertainty. The person setting the type doesn’t know styles three, four, five or six even exist but does know that Titles Are Somehow Different To Standard Text When It Comes To Capitals. Consequently, and by way of obviating the problem, they stick Initial Caps on everything.

The New York Times variant on style five noted above — initial caps for everything, except non-initial closed class words, unless the non-initial closed-class word is particularly long — is popular, albeit accidentally so. Most people using it are actually using a naive version of it: initial caps for everything except short words, unless the short words are nouns or names or the like.

Given the complexity even the simplest of these rules introduce, the argument for simple sentence case is compelling. It reduces the editorial workload and doesn’t materially effect the look of the published material.

The only half-decent justification for anything other than standard sentence case is your titles not being set in clear and contrasting style to body copy.

A better solution to that problem is to re-set the titles, not introduce complicated house rules that people will invariably forget.

Set your titles and heads and sub-heads in a clear and contrasting typeface and the half-decent justification for using anything other than standard sentence case goes away.

1. Closed class word types don’t get new members all that often.² For example, prepositions, postpositions, determiners, conjunctions, & pronouns. Nouns and verbs, by contrast, are open class words, taking on new members all the time.

2. All that often is not the same as never.