That yellow color 19 Mok Cheong St plate is not a government street sign , in many old district you can find some of the shops they had number and street name plastic plate stick on the facade , was make by the property owner .
Hello May! T字路牌係97年前殖民時代用，所以都係仿照英式路牌設計，你可以搜尋old London street signs對比一下，至於點解會係T型，我估計係因為要中英對照，加咗一行中文街名，而香港嘅中文街名多數三個字，比較英文街名排列會短少少，將兩旁多餘的空白位置減去，形成T形路牌，不過以上純粹我個人估計，如果有朋友熟知香港歷史，請更正！🙏
The sign for 19 Mok Cheong St is not a street sign. It is actually a house sign telling you it is #19. It looks to be relatively new because the Chinese are written from left to right. You can actually find that exact sign on google map street view.
