Have you ever seen these dark marks on the pavement? They are normally the remnants of a praying session, where paper incense was offered and burnt. In the wee hours of the morning, the estate cleaner has already swept up the paper ashes, so these are the marks left by the burning. If you can, try to avoid walking across these marks. And if you really cannot avoid, just say a silent “excuse me” as you walk across the marks. Call it superstition, call it whatever. But it won’t harm you by making a slight detour to the grass area, as shown in the photo below.