Which statements make it clear that the player wants to play a provisional ball?

It is always best to use the word "PROVISORY":

See also Rule 18.3b

18.3b Announcement to play a provisional ball
Before the player strikes, he must announce that he intends to play a provisional ball:
- It is not sufficient for the player merely to say that he is playing another ball or playing again.
- The player must use the word "provisional" or otherwise make it clear that he is playing the ball provisionally in accordance with Rule 18.3.

If the player does not announce this (even if he intended to play a provisional ball) and plays a ball from the spot from which the previous stroke was made, that ball is in play with penalty of stroke and loss of distance of the player's ball (see Rule 18.1).

Which statements - make it clear and which do not - that you want to play a provisional ball.

18.3b/2 - Statements that "make it clear" that a provisional ball is being played
When playing a provisional ball, it is best if the player uses the word "provisional" in his announcement. However, other statements that make it clear that it is the player's intention to play a provisional ball are also acceptable.

Examples of announcements that make it clear that the player is playing a provisional ball include:
- "I am playing a Rule 18.3 ball."
- "I will play another ball to be on the safe side."

Examples of announcements that do not make it clear that the player intends to play a provisional ball and mean that the player would put a ball into play with a stroke and loss of distance include:
- "I'm going to reload."
- "I'll play another one."

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