f - full timer tick plus link

Author: jkczyz

lightning/src/ln/channelmanager.rs

@@ -4003,14 +4003,17 @@ where
 	/// fails or if the encoded `payment_id` is not recognized. The latter may happen once the
 	/// payment is no longer tracked because the payment was attempted after:
 	/// - an invoice for the `payment_id` was already paid,
-	/// - one timer tick has elapsed since initially requesting the invoice when paying an offer, or
+	/// - one full [timer tick] has elapsed since initially requesting the invoice when paying an
+	///   offer, or
 	/// - the refund corresponding to the invoice has already expired.
 	///
 	/// Attempting to pay the same invoice twice while the first payment is still pending will
 	/// result in a [`Bolt12PaymentError::DuplicateInvoice`].
 	///
 	/// Otherwise, either [`Event::PaymentSent`] or [`Event::PaymentFailed`] are used to indicate
 	/// whether or not the payment was successful.
+	///
+	/// [timer tick]: Self::timer_tick_occurred
 	pub fn send_payment_for_bolt12_invoice(&self, invoice: &Bolt12Invoice) -> Result<(), Bolt12PaymentError> {
 		let secp_ctx = &self.secp_ctx;
 		let expanded_key = &self.inbound_payment_key;