USA - Registered Mail Notice (for paper products only)
Do take note if you're residing in the USA and your order consists of only paper products! You can always call up USPS to check on the status after it reaches the destination country for a quicker response.
The text below is quoted directly from Singpost:
The designated operator of USA, USPS, has informed that from 1 October 2015, online tracking and delivery information for registered letter mail sent from Singapore to USA will not be visible or available on USPS website www.usps.com. Hence, tracking information is only available up to "Arrival at Destination Post" on SingPost website.
Customers in Singapore can raise enquiry with SingPost if the addressee confirms non-receipt of the Registered Article after 18 working days from posting. SingPost will check with the USPS on the status of the item, and under the international postal agreement, USPS may take up to 60 days to reply to SingPost.