IV is short for 'initialization vector'

src/encauth/chachapoly/chacha20poly1305_memory.c

@@ -15,8 +15,8 @@
   Process an entire GCM packet in one call.
   @param key               The secret key
   @param keylen            The length of the secret key
-  @param iv                The initial vector
-  @param ivlen             The length of the initial vector
+  @param iv                The initialization vector
+  @param ivlen             The length of the initialization vector
   @param aad               The additional authentication data (header)
   @param aadlen            The length of the aad
   @param in                The plaintext

src/encauth/gcm/gcm_memory.c

@@ -20,8 +20,8 @@
   @param cipher            Index of cipher to use
   @param key               The secret key
   @param keylen            The length of the secret key
-  @param IV                The initial vector
-  @param IVlen             The length of the initial vector
+  @param IV                The initialization vector
+  @param IVlen             The length of the initialization vector
   @param adata             The additional authentication data (header)
   @param adatalen          The length of the adata
   @param pt                The plaintext