2. Consistency and spelling matters

Consistency in punctuation, capitalization, spelling, hyphenation, and abbreviation is essential to maintaining the highest standard possible in any journal. Typical corrections for consistency include the following: halos/haloes; online/on-line/on line; 3D/3-D/3 D/ three-dimensional; versus/vs./vs/v/against; the serial comma in lists (as recommended by A&A for clarity: see Sect. 3.1.3); hyphenation or merging of prefixes.

The author must choose between these possibilities for the whole MS, even if all are correct.

2.1 US vs UK conventions

The inconsistency that we have to correct most is the mixture of American (US) and British (UK) spelling and conventions in the same MS, so the chart below indicates which form belongs to which set of conventions out of the words that we see most often.

UK spelling conventions US spelling conventions
-OUR endings:
behaviour, neighbour, favour, colour, harbour, vapour
-OR endings: behavior, neighbor, favor, color, harbor, vapor
(NB, but “contour” since pronounced /oor/)
-RE endings:
centre, metre, fibre, calibre
-ER endings:
center, meter, fiber, caliber
-SE endings on some verbs (less often for scientific terms) or -ISATION on nouns. analyse, summarise, organisation, ionise, etc.
It is possible to use IZE/IZATION but only if consistent1 to practise (noun=practice, e.g., in practice)
-ZE on the same verbs, IZATION on the nouns:
analyze, summarize, organize, ionization, to practice
ISE verbs in both languages: advise, surprise, supervise, comprise
-DS/ST adverb endings:
towards, outwards, amidst, amongst, whilst (OK amid & among)
Few if any of these are used in US spelling.
Generally doubled consonants on suffixes:
modelled, labelling, travelling, cancelling, cancellation
Single consonant for suffixes if pronunciation does not change:
modeled, labeled, traveling, canceling, cancelation
on-line, non-zero, north-east, south-west, multiwavelength, redshift, ultraviolet, infrared.
If any of these are merged, then they must be consistent and used for both adjective and noun forms.
Usually merged, not hyphenated:
online, northeast, southwest, nonzero (not strict for the non- prefix), multiwavelength, but pre-existing, non-negligible since the last prefix letter is repeated in the root noun.
-LOGUE ending:
catalogue, analogue, isotopologue
-LOG ending: catalog, analog, & isotopolog (the –gue is still seen, but be consistent)
Other words & expressions:
of the order, in the order of
brackets & square brackets
further (accepted for distance, but not preferred)

autumn, artefact, ageing, grey, speciality
sulphur, aluminium
to orientate, to fulfil (but fulfilled), to inquire
near to, opportunity to do (or possibility)
on the order of
parentheses & brackets
Stricter on the difference of farther for physical distance & further for more figurative uses.

fall, artifact, zero, gray, aging, specialty
sulfur, aluminum
to orient, to fulfill, to enquire
near, opportunity of doing (or possibility)
commas need not be placed around “e.g.” or “i.e.”, or should be used consistently if chosen;
fewer commas can be used for introductory phrases and between sentences, but are needed if ambiguous without them.
commas surround “e.g.” & “i.e.”, as for their full forms in the running text: “(see, e.g., Newton 1687)”;
commas are used more consistently for introductory phrases & between full sentences with connectors.

1 The IZE/IZATION choice is acceptable in UK conventions (except for “analyse”), but once the ISE/ISATION endings have been chosen in a UK MS, then it should be used consistently with one exception: all endings use the S except for the technical words (e.g., ionize, parametrization), if the author prefers.

2.2 Hyphenation or merging

There are rules about when to hyphenate, when to leave something separate, or when to merge. Some are fixed rules, others vary between the US and UK dialects, and still others can vary depending on whether it is ambiguous with or without the punctuation or merging. The policy is that once you use a form, you must be consistent with it unless there is an exceptional reason for a change.

2.2.1 Word-forming prefixes

Both UK and US dialects use merged and hyphenated word forms. The US spelling tends to merge common prefixes on compound nouns or adjectives, and the UK spelling is more likely to hyphenate (e.g., multi-, over-, non-). A good dictionary will give the spelling and variants, but A&A requires consistency within the same paper. LEs will always attach any prefix that is separate from the root word:

  • “non relational database”
  • “non-relational” or “nonrelational”.

Hyphenated in both dialects are the following:

  • Compounds where the second element is capitalized or a numeral:

    “exo-Earths”, “pre-1914”;

  • Compounds where the last letter of the prefix is the same as the first letter of the root word:


  • Compounds in which the second element consists of more than one word:

    “pre-main sequence star” or “pre-main-sequence star”. (Only the second hyphen is optional, since it is now an established pair.);

  • Compounds that must be distinguished from homonyms:

    “un-ionized”, “re-creation”.

2.2.2 Strings of adjectives with compound nouns or adjective noun pairs

When there is more than one modifier before a final noun, then commas or hyphens may be needed to clarify the relationships of the different modifiers before the noun, whether to each other or to the noun.

When there are several adjectival words or phrases, each one referring directly to the noun and not to the other modifiers, then commas are used to separate them by replacing the “and” that is implied.

“It is a light-weight, battery-operated, fully ambulatory physiological monitoring system” (taken from p. 140 of Minimum Competence in Scientific English, nouvelle édition, by S. Blattes et al., Grenoble Sciences and EDP Sciences, 2003).

The more noun modifiers used in a noun phrase, the more this punctuation and spelling are needed, since it is difficult for the reader to tell when the final noun has arrived. Another clue is whether the noun modifiers have no plural S, though the plural meaning is likely (Sect. 5.2).

“This modification involves a cluster mass dependent gas mass fraction.” (Does this correct to “a cluster's mass-dependent gas-mass fraction” or something else?)
There can also be too many such modifiers, however, so that some phrases need to be expanded back to the standard prepositional forms.

“covering a wide age-distance-metallicity-position-density parameter space.”
Should this be “covering a wide parameter space of ages, distances, metallicities, positions, and densities”?

If there are too many noun or other modifiers preceding the final noun, so that it becomes very confusing, then some of these phrases could be changed back to an expanded form.

  • “electrically conducting ionized gas particles”
  • “ionized gas particles that conduct electrically”
  • “with observational evidence of quasar feedback quenching star formation at high redshift”

(It is hard to tell whether “quenching” is a noun with “quasar-feedback quenching” or “quenching of quasar feedback”, or is it meant as a verb here, that is, “quasar feedback that quenches”?)

2.2.3 Compounds with a participle modifying a noun that follows it

wide-spread theory, decision-making procedure, hard-working student, remote-controlled detector, star-forming region (but “star formation region”).

2.2.4 Some exceptions

  • Once a noun pair has become widespread, then the hyphen is no longer needed to avoid ambiguity, except in very long noun phrases with a string of these modifiers (see example at the end of Sect. 2.2.2): e.g., “main sequence star”.
  • The comparative and superlative adjective forms are not hyphenated unless the reference is ambiguous:

    “low-mass star”, but “lower mass star” or “lowest mass star”.

  • Two-word Latin terms are neither hyphenated nor italicized:

    “an ad hoc formula”.