From a Times Insider column by Terence McGinley “A Newsletter for Spanish Speakers and Learners”:

Most words in the headline of a New York Times article are capitalized. But capitalization is sparsely employed in the Spanish language, which uses the lowercase for many proper nouns and titles. So when Elda Cantú and her team translate Times articles from English to Spanish, they might lowercase a few letters.

“We work quickly and with a global understanding, but we respect Spanish rules,” Ms. Cantú said of The Times’s Spanish-language operation, which she runs from Mexico City.