Halfbloods in Slytherin? Photo section list of students

[Julie]

No: HPFGUIDX 93787

 {Majorly snipped) Pippin and Annemehr were discussing the photo 
section file "Harry Potter" with slides of a book with a list of 
students.<<<<<< [Pippin said]proceed ahead to pics #14 and #15, 
looking at the list of students, look at the symbols in the middle 
column, which seem to stand for muggle/wizard origins.  >>>>>>>

Never looked in that file until your comments refered to it.  What is 
this book and any idea what the first column of circles and filled in 
squares refers to?  

Inky/Julie