All rights not expressly granted herein are reserved by Span.</p>18. Waiver<p>Failure or delay by us to enforce any of these Terms &amp. Conditions will not constitute a waiver of our rights against you and does not affect our right to require future performance thereof.</p>19. Headings<p>Headings and captions are for convenience only and are not to be used in the interpretation of these Terms &amp. Conditions.</p>20. Electronic Communications<p>You are communicating with Span electronically when you use Span’s website or send email to Span.