diff --git a/include/osmocom/core/rate_ctr.h b/include/osmocom/core/rate_ctr.h
index 4fecdfa..cdde353 100644
--- a/include/osmocom/core/rate_ctr.h
+++ b/include/osmocom/core/rate_ctr.h
@@ -78,6 +78,7 @@
 
 void rate_ctr_group_free(struct rate_ctr_group *grp);
 
+/*! \brief Increment the counter by \a inc */
 void rate_ctr_add(struct rate_ctr *ctr, int inc);
 
 /*! \brief Increment the counter by 1 */
diff --git a/include/osmocom/gsm/apn.h b/include/osmocom/gsm/apn.h
index d8d7399..a256d97 100644
--- a/include/osmocom/gsm/apn.h
+++ b/include/osmocom/gsm/apn.h
@@ -9,5 +9,8 @@
 #define APN_MAXLEN	100
 
 char *osmo_apn_qualify(unsigned int mcc, unsigned int mnc, const char *ni);
+
+/* Compose a string of the form '<ni>.mnc001.mcc002.gprs\0', returned in a
+ * static buffer. */
 char *osmo_apn_qualify_from_imsi(const char *imsi,
 				 const char *ni, int have_3dig_mnc);
diff --git a/include/osmocom/gsm/protocol/gsm_08_58.h b/include/osmocom/gsm/protocol/gsm_08_58.h
index 530bbc8..56cf4dd 100644
--- a/include/osmocom/gsm/protocol/gsm_08_58.h
+++ b/include/osmocom/gsm/protocol/gsm_08_58.h
@@ -82,7 +82,7 @@
 /* \brief Check if given RSL message discriminator is transparent */
 #define ABIS_RSL_MDISC_IS_TRANSP(x)	(x & 0x01)
 
-/* \brief RSL Message Tyoe (Chapter 9.1) */
+/* \brief RSL Message Type (Chapter 9.1) */
 enum abis_rsl_msgtype {
 	/* Radio Link Layer Management */
 	RSL_MT_DATA_REQ			= 0x01,
diff --git a/include/osmocom/gsm/tlv.h b/include/osmocom/gsm/tlv.h
index d54ef1a..c19034f 100644
--- a/include/osmocom/gsm/tlv.h
+++ b/include/osmocom/gsm/tlv.h
@@ -402,7 +402,7 @@
                   const uint8_t *buf, int buf_len);
 int tlv_parse(struct tlv_parsed *dec, const struct tlv_definition *def,
 	      const uint8_t *buf, int buf_len, uint8_t lv_tag, uint8_t lv_tag2);
-/* take a master (src) tlvdev and fill up all empty slots in 'dst' */
+/* take a master (src) tlv def and fill up all empty slots in 'dst' */
 void tlv_def_patch(struct tlv_definition *dst, const struct tlv_definition *src);
 
 #define TLVP_PRESENT(x, y)	((x)->lv[y].val)