can anyone tell me what type of indent is ued ia a reference list?

If you mean the indentation so that the first line of a reference starts at the left margin and all other lines start about half an inch to the right, it's called a hanging indent.

If you're using Word, you can set these easily. Highlight what you want to have this hanging indentation. Then go to Format | Paragraph and then click on Special in the Indentation section and choose Hanging. The program should set a value of 0.5" -- then click on OK.