ASK A QUESTION what does hache mean
what does the phrase Se escribe con hache mayuscula when used in looking at a editorial staff of a spanish magazine
You'll find the answer easily right here on the dictionary tab of Span¡shd!ct.com, kutter5. http://www.spanishdict.com/translate/hache
Hache is the letter "h"! And your sentence is talking about a capital "H". http://www.spanishdict.com/translate/mayúscula
But please note that "mayúscula" might have been "mayúsculo" had whatever noun it was describing been masculine instead of feminine in gender.
And also note that the pronunciation of "mayúscula" requires the accented ú. I imagine that it is actually accented in what you read?
¿Cómo se escribe?¿Con hache?