Ch. 1 · 第２節 信号
In a location where there is a "Sound Horn" sign, you must sound your horn, but this is classified as a regulatory sign rather than an indication sign.
[True / False · Hard]
Answer: False
Explanation
"Sound Horn" is an indication sign. According to the Rules of the Road, indication signs designate that certain traffic methods are permitted or instruct specific actions. Because it instructs you to sound your horn, it is classified as an indication sign.
Source: Ch. 1 · Section (第２節 信号) · 第２節 信号、標識・標示に従うこと（2. 標識の意味）
See the glossary for definitions of key terms.