diff --git a/help/mat b/help/mat
index 29c7062..1680ede 100644
--- a/help/mat
+++ b/help/mat
@@ -54,13 +54,13 @@ DESCRIPTION
     The elements of the matrix are stored internally as a linear array
     in which locations are arranged in order of increasing indices.
     For example, in order of location, the six element of A = mat [2,3]
-    are
+    are:
 
-	A[0,0], A[0,1], A[0,2], A[1,0], A[1,,1], A[1,2].
+	A[0,0], A[0,1], A[0,2], A[1,0], A[1,1], and A[1,2].
 
     These elements may also be specified using the double-bracket operator
     with a single integer index as in A[[0]], A[[1]], ..., A[[5]].
-    If p is assigned the value &A[0.0], the address of A[[i]] for 0 <= i < 6
+    If p is assigned the value &A[0,0], the address of A[[i]] for 0 <= i < 6
     is p + i as long as A exists and a new value is not assigned to A.
 
     When a matrix is created, each element is initially assigned the
@@ -414,7 +414,7 @@ SEE ALSO
     det, inverse, isident, test, config, search, rsearch, reverse, copy,
     blkcpy, dp, cp, randperm, sort
 
-## Copyright (C) 1999-2006  Landon Curt Noll
+## Copyright (C) 1999-2006,2018  Landon Curt Noll
 ##
 ## Calc is open software; you can redistribute it and/or modify it under
 ## the terms of the version 2.1 of the GNU Lesser General Public License
diff --git a/help/randbit b/help/randbit
index 7c83dfe..4e2e489 100644
--- a/help/randbit
+++ b/help/randbit
@@ -1,5 +1,5 @@
 NAME
-    randbit - additive 55 shuffle pseudo-random number generator
+    randbit - subtractive 100 shuffle pseudo-random number generator
 
 SYNOPSIS
     randbit([x])
@@ -42,7 +42,7 @@ LINK LIBRARY
 SEE ALSO
     seed, srand, randbit, isrand, random, srandom, israndom
 
-## Copyright (C) 1999  Landon Curt Noll
+## Copyright (C) 1999,2018  Landon Curt Noll
 ##
 ## Calc is open software; you can redistribute it and/or modify it under
 ## the terms of the version 2.1 of the GNU Lesser General Public License
diff --git a/help/seed b/help/seed
index 033fcaf..83a5289 100644
--- a/help/seed
+++ b/help/seed
@@ -18,14 +18,7 @@ DESCRIPTION
 	It should be pointed out that the information collected by seed
 	is almost certainly non-chaotic.  This function is likely not
 	suitable for applications (such as cryptographic applications)
-	where the unpredictability of seeds is critical.  For such critical
-	applications, LavaRnd should be used.	See the URL:
-
-		http://www.LavaRnd.org/
-
-	for information about seeding a pseudo-random number generator
-	(such as rand() or random()) with the cryptographic hash of the
-	digitization of chaotic system.
+	where the unpredictability of seeds is critical.
 
     Given the above warning, this builtin function produces a seed that is
     suitable for most applications that desire a different pseudo-random
@@ -51,7 +44,7 @@ LINK LIBRARY
 SEE ALSO
     seed, srand, randbit, isrand, rand, random, srandom, israndom
 
-## Copyright (C) 1999  Landon Curt Noll
+## Copyright (C) 1999,2018  Landon Curt Noll
 ##
 ## Calc is open software; you can redistribute it and/or modify it under
 ## the terms of the version 2.1 of the GNU Lesser General Public License
diff --git a/help/srandom b/help/srandom
index 68347cb..defce60 100644
--- a/help/srandom
+++ b/help/srandom
@@ -332,13 +332,13 @@ LIMITS
     iq >= 2^16
 
 LINK LIBRARY
-    RAND *zsrandom(ZVALUE *pseed, MATRIX *pmat55)
-    RAND *zsetrandom(RAND *state)
+    RANDOM *zsrandom(ZVALUE *pseed, MATRIX *pmat55)
+    RANDOM *zsetrandom(RAND *state)
 
 SEE ALSO
     seed, srand, randbit, isrand, random, srandom, israndom
 
-## Copyright (C) 1999  Landon Curt Noll
+## Copyright (C) 1999,2018  Landon Curt Noll
 ##
 ## Calc is open software; you can redistribute it and/or modify it under
 ## the terms of the version 2.1 of the GNU Lesser General Public License
diff --git a/help/types b/help/types
index c2329d5..99bdc38 100644
--- a/help/types
+++ b/help/types
@@ -1,6 +1,6 @@
 Builtin types
 
-    The calculator has the following built-in types.
+    The calculator has the following built-in types:
 
     null value
 	    This is the undefined value type.  The function 'null'
@@ -101,7 +101,20 @@ Builtin types
 	    using the result of the 'files' function.  Such copies are
 	    indistinguishable from each other.
 
-## Copyright (C) 1999  Landon Curt Noll
+    The calculator also has a number of special types that as used
+    by some special builtin functions:
+
+    rand
+	    A subtractive 100 shuffle pseudo-random number generator
+	    state.  This state is used by functions such as isrand()
+	    and srand().
+
+    random
+	    A Blum-Blum-Shub pseudo-random number generator state.
+	    This state is used by functions such as israndom() and
+	    srandom().
+
+## Copyright (C) 1999,2018  Landon Curt Noll
 ##
 ## Calc is open software; you can redistribute it and/or modify it under
 ## the terms of the version 2.1 of the GNU Lesser General Public License