Оказывается, иногда полезно читать хелпы.

Когда понадобилось, сразу нашел
Цитата
Like in C, source lines can be continued by means of having a backslash (\) as the last character of a line. This is particularly useful when defining long preprocessor macros, and for long .db directives.
Example
.db 0, 1, "This is a long string", '\n', 0, 2, \
"Here is another one", '\n', 0, 3, 0