Email wording

Both emails are written in the Wording section of the settings screen, three boxes per email — the subject, the plain-text part and the HTML part — one language at a time. These are the placeholders they may use. Anything else inside braces is left exactly as you typed it, so prose containing a brace survives.

Placeholder	What it is filled with
{product}	The product's name, in the language the shopper signed up in.
{option}	The variant, as — Medium, and nothing at all where the watch names no option value. Written to sit straight after {product}.
{store}	The store's name, from System > Settings.
{product_url}	A link to the product page, on the store the shopper signed up on.
{unsubscribe_url}	The one-click unsubscribe link. Every alert has to carry one.
{confirm_url}	The link that confirms the address. Nothing is ever sent to an address that has not been confirmed, so this belongs in the confirmation email and nowhere else.
{store_email}	The store's own email address.
{store_address}	The store's postal address, which every alert has to carry.
{expiry}	How long an unconfirmed sign-up is kept before it is deleted, as words.

Values are escaped for the HTML part and left raw for the plain-text part, which is what keeps a link with a query string clickable in a plain-text client.

Leave a box empty and Back In Stock's own wording is used, shown in the box in grey. What you write survives an update, which is the difference between this and the files under extension/back_in_stock/data/mail/ these used to be: those are still shipped, are no longer read, and come out of the package in a later release.