What does square bracket and letter prefix mean in the java jmap histogram?

Question

What does square bracket and letter prefix mean in the jmap histogram?

For example: [L and [C below?

The doc https://docs.oracle.com/javase/8/docs/technotes/guides/troubleshoot/tooldescr014.html#BABJIIHH only mention angle bracket which means internal JVM classes.

 num     #instances         #bytes  class name
----------------------------------------------
   1:     376182087     9028370088  org.joda.time.DateTime
   2:     376179680     9028312320  **REDACTED**
   3:        655038     2163947376  [Ljava.lang.Object;
   4:       1374798      174768304  [C
   5:       2595945       62302680  java.lang.String
   6:        117265       34652352  [B
   7:        242416       25892568  [Ljava.util.HashMap$Node;
   8:         76675       20546128  [I
   9:        568297       18185504  java.util.HashMap$Node
  10:        161383       14201704  java.lang.reflect.Method
  11:        590604       14174496  java.util.ArrayList
  12:        349188       13967520  java.util.LinkedHashMap$Entry
...truncated...