Is there a similar convention to using an asterisk in English to signify the presence of a disclaimer in Japanese? For example, in English, you might see, "Order now for $19.99*" then somewhere else on the same document, you may see, "* Prices displayed are pre-tax."
Or is it more common to place the disclaimer next to a price, such as "Order now for $19.99 (pre-tax)"
This is a common practice also in Japanese (called 脚注 "footnotes"). But Japanese people tend to use superscript kome-jirushi (※) instead of the asterisk. When there are many footnotes, numbered kome-jirushi (※1 ※2 ...) are normally used instead of the daggers († ‡). See Note_(typography).
In CJK languages, written with Chinese characters, the symbol ※ (called reference mark; Japanese: komejirushi; Korean: chamgopyo) is used for notes and highlighting, analogously to the asterisk in English.
That said, something short like 税抜き ("tax excluded") should be preferably shown next to the price. Saying 税抜き only on a footnote works, but looks sly to me.
