Rank 1 White Howler Gift
When this Gift is active, glowing sigils representing the Garou’s tales of Renown appear upon their skin or pelt. The marks shine a luminescent woad-blue, although Honor, Glory, and Wisdom all gleam with their own subtle inflections of color. Temporary Renown appears as reinforcing details on the permanent Renown symbols. This gift is taught by a Lune spirit.
System: While this Gift is active, the Garou receives a pool of bonus dice equal to his rank that he can allocate towards any Social rolls (including intimidation) towards spirits or other Gaian Garou until the remainder of the scene.
Source: White Howler Tribebook
How do you activate it? The book doesn’t say.
Since the book doesn’t say, it’s up to Storyteller discretion. I would say it can be activated at will, myself.