For example, a scientific paper with a heading such as:

MERCURY AND AMAZONIAN FISH SPECIES

is vague. It does not reveal anything about the nature of the study.

On the other hand a title such as:

MERCURY IS A SIGNIFICANT CONTAMINANT OF AMAZONIAN FISH SPECIES

is considered too sensational for a scientific paper. The title could be re-phrased as:

MERCURY CONTAMINATION IN AMAZONIAN FISH SPECIES

This provides some indication of the concern without using terms such as 'significant'. Notice that redundant words, such as verbs and articles, have been eliminated, so that the title functions as a label rather than a sentence.