diff --git a/util.py b/util.py
index 45e2502f8..dc78ffb79 100644
--- a/util.py
+++ b/util.py
@@ -1,19 +1,48 @@
 def shorten(val, prec=4, lowest=0, highest=0):
+    """
+    Add suffix to value, transform value to match new suffix and round it.
+
+    Keyword arguments:
+    val -- value to process
+    prec -- precision of final number (number of significant positions to show)
+    lowest -- lowest order for suffixizing
+    highest -- highest order for suffixizing
+
+    Suffixes below lowest and above highest orders won't be used.
+    """
+    # Take numbers only matching/above lowest possible positive suffix
     if abs(val) >= 1000 and highest >= 3:
         suffixmap = {3 : "k", 6 : "M", 9 : "G"}
+        # Start from highest possible suffix
         for key in sorted(suffixmap, reverse = True):
+            # Find first suitable suffix and check if it's not above highest order
             if val >= 10**key and key <= highest:
                 return u"{0}{1}".format(process(val/float(10**key), prec), suffixmap[key])
+    # Take numbers between 0 and 1, and matching/below highest possible negative suffix
     elif abs(val) < 1 and val != 0 and lowest <= -3:
         suffixmap = {-6 : u'\u03bc', -3 : "m"}
+        # Start from lowest possible suffix
         for key in sorted(suffixmap, reverse = False):
+            # Check if mantissa with next suffix is in range [1, 1000)
+            # Here we assume that each next order is greater than previous by 3
             if val < 10**(key+3) and key >= lowest:
                 return u"{0}{1}".format(process(val/float(10**key), prec), suffixmap[key])
+    # No suitable suffixes are found withing given order borders, or value
+    # is already within [1, 1000) boundaries, just return rounded value with no suffix
     else:
         return u"{0}".format(process(val, prec))
 
 
 def process(val, prec):
+    """
+    Round number.
+
+    Keyword arguments:
+    val -- value to round
+    prec -- precision of final number (number of significant positions to show)
+
+    Integer numbers are not rounded, only fractional part.
+    """
     # Check if we have no integer and some fraction after bunch of zeroes,
     # counting these zeros in process
     shiftFraction, integersNumber = 0, 0