In the So Sethaputra online dictionary, what is the dot used for below a character?

As Mr. Setheputra mentions in the Preface of his "Modern Thai-English Dictionary," the mark "." is used to avoid misreading. Take for example, the word "แปฺลง" should be read "plang" not "pa-long." Please notice the "pl." Without this mark, you then might read "pa-long," which is wrong.

Likewise, "เหฺลี่ยม" should be read "leam"; "กฺริยา" "kri-ya."
Of course, without the mark, "กฺริยา" may be read "ka-ri-ya," which is wrong. (I don't want to make this more complicated but "ka-ri-ya" is spelled "กิริยา")

w-bpf