This post is a little off-topic, but perhaps will help people Googling with the same problem.
A trivial issue nearly prevented me from being able to determine the status of my Hong Kong visa application online. The reference number I’d been given was of the form XXXX-nnnn-nn – four letters, four digits, then another two digits:
When I tried submitting the code exactly as (hand-)written on my receipt, the system told me the number was invalid:
For some reason the programmer in me thought, “surely it couldn’t be that the fields have to be zero padded?” – so I tried adding zeros to the middle field until the form would allow no more. Now displaying “XXXX-000nnnn-nn”, I submitted the form, and was amazed to see that it worked! Presumably the software makes a string comparison even for the numeric fields, so the reference number must have exactly 7 digits in the middle field:
In my case it turned out that being able to check online was very useful, as nobody was answering the phone at the relevant immigration department, and once I was finally able to check online, I discovered that my application was already approved and ready to collect.
I couldn’t find any mention of this in the instructions, and it certainly wasn’t obvious from the error message (I’d assumed that my application must by of the “not supported” type) – perhaps this report will help someone else check their status (or help someone at the immigration department fix their software/error message).