diff --git a/src/libvlr/vlr_access_req_fsm.c b/src/libvlr/vlr_access_req_fsm.c
index 279e3d4..15f84b7 100644
--- a/src/libvlr/vlr_access_req_fsm.c
+++ b/src/libvlr/vlr_access_req_fsm.c
@@ -172,6 +172,7 @@
 
 	LOGPFSM(fi, "%s()\n", __func__);
 
+	/* See 3GPP TS 29.002 Proc_Acc_Req_VLR3. */
 	/* TODO: Identity := IMSI */
 	if (0 /* TODO: TMSI reallocation at access: vlr->cfg.alloc_tmsi_arq */) {
 		vlr_subscr_alloc_tmsi(vsub);
@@ -194,6 +195,7 @@
 	LOGPFSM(fi, "%s()\n", __func__);
 
 	/* Node 3 */
+	/* See 3GPP TS 29.002 Proc_Acc_Req_VLR3. */
 	if (0 /* IMEI check required */) {
 		/* Chck_IMEI_VLR */
 		vlr->ops.tx_id_req(par->msc_conn_ref, GSM_MI_TYPE_IMEI);
@@ -207,6 +209,7 @@
 static void _proc_arq_vlr_post_pres(struct osmo_fsm_inst *fi)
 {
 	LOGPFSM(fi, "%s()\n", __func__);
+	/* See 3GPP TS 29.002 Proc_Acc_Req_VLR3. */
 	if (0 /* TODO: tracing required */) {
 		/* TODO: Trace_Subscriber_Activity_VLR */
 		osmo_fsm_inst_state_chg(fi, PR_ARQ_S_WAIT_TRACE_SUB, 0, 0);
@@ -227,6 +230,7 @@
 		proc_arq_fsm_done(fi, VLR_PR_ARQ_RES_UNIDENT_SUBSCR);
 		return;
 	}
+	/* We don't feature location area specific blocking (yet). */
 	if (0 /* roaming not allowed in LA */) {
 		/* Set User Error: Roaming not allowed in this LA */
 		proc_arq_fsm_done(fi, VLR_PR_ARQ_RES_ROAMING_NOTALLOWED);
diff --git a/src/libvlr/vlr_lu_fsm.c b/src/libvlr/vlr_lu_fsm.c
index d32659f..f9ccbdf 100644
--- a/src/libvlr/vlr_lu_fsm.c
+++ b/src/libvlr/vlr_lu_fsm.c
@@ -760,7 +760,9 @@
 {
 	LOGPFSM(fi, "%s()\n", __func__);
 
-	/* FIXME */
+	/* OsmoHLR does not support PgA, neither stores the IMEISV, so we have no need to update the HLR
+	 * with either. TODO: depend on actual HLR configuration. See 3GPP TS 23.012 Release 14, process
+	 * Update_Location_Area_VLR (ULA_VLR2). */
 	if (0) { /* IMEISV or PgA to send */
 		vlr_loc_upd_node_4(fi);
 	} else {
@@ -1149,6 +1151,7 @@
 			/* unsuccessful case */
 			enum gsm48_gmm_cause cause =
 				*(enum gsm48_gmm_cause *)data;
+			/* Ignoring standalone mode for now. */
 			if (0 /* procedure_error && vlr->cfg.standalone_mode */) {
 				osmo_fsm_inst_state_chg(fi,
 						VLR_ULA_S_WAIT_LU_COMPL_STANDALONE,