diff --git a/scripts/base/protocols/conn/main.zeek b/scripts/base/protocols/conn/main.zeek
index 015b854df2..bd8a8d1261 100644
--- a/scripts/base/protocols/conn/main.zeek
+++ b/scripts/base/protocols/conn/main.zeek
@@ -240,7 +240,7 @@ function set_conn(c: connection, eoc: bool)
 	{
 	if ( ! c?$conn )
 		{
-		local tmp: Info &is_set;
+		local tmp: Info &is_assigned;
 		c$conn = tmp;
 		}
 
diff --git a/scripts/base/protocols/dns/main.zeek b/scripts/base/protocols/dns/main.zeek
index 955c3d5eae..4f48e510bc 100644
--- a/scripts/base/protocols/dns/main.zeek
+++ b/scripts/base/protocols/dns/main.zeek
@@ -293,7 +293,7 @@ hook set_session(c: connection, msg: dns_msg, is_query: bool) &priority=5
 				else
 					{
 					# Just pick an arbitrary, unpaired query.
-					local tid: count &is_set;
+					local tid: count &is_assigned;
 					local found_one = F;
 
 					for ( trans_id, q in c$dns_state$pending_queries )
diff --git a/scripts/base/protocols/ftp/utils-commands.zeek b/scripts/base/protocols/ftp/utils-commands.zeek
index 037055a42a..43519b8422 100644
--- a/scripts/base/protocols/ftp/utils-commands.zeek
+++ b/scripts/base/protocols/ftp/utils-commands.zeek
@@ -87,7 +87,7 @@ function add_pending_cmd(pc: PendingCmds, cmd: string, arg: string): CmdArg
 # response code and message.
 function get_pending_cmd(pc: PendingCmds, reply_code: count, reply_msg: string): CmdArg
 	{
-	local best_match: CmdArg &is_set;	# &is_set for $ts field
+	local best_match: CmdArg &is_assigned;	# &is_assigned for $ts field
 	local best_seq = 0;
 	local best_score: int = -1;
 
diff --git a/scripts/base/protocols/ntp/main.zeek b/scripts/base/protocols/ntp/main.zeek
index 6f870af7f8..d922ae39e3 100644
--- a/scripts/base/protocols/ntp/main.zeek
+++ b/scripts/base/protocols/ntp/main.zeek
@@ -66,7 +66,7 @@ event zeek_init() &priority=5
 
 event ntp_message(c: connection, is_orig: bool, msg: NTP::Message) &priority=5
 	{
-	local info: Info &is_set;	# &is_set for case where no $std_msg
+	local info: Info &is_assigned;	# for case where no $std_msg
 	info$ts  = network_time();
 	info$uid = c$uid;
 	info$id  = c$id;
diff --git a/scripts/base/protocols/ssh/main.zeek b/scripts/base/protocols/ssh/main.zeek
index cb38afee13..f2b5d52e5c 100644
--- a/scripts/base/protocols/ssh/main.zeek
+++ b/scripts/base/protocols/ssh/main.zeek
@@ -142,7 +142,7 @@ function set_session(c: connection)
 	{
 	if ( ! c?$ssh )
 		{
-		local info: SSH::Info &is_set;	# needed for $version
+		local info: SSH::Info &is_assigned;	# needed for $version
 		info$ts  = network_time();
 		info$uid = c$uid;
 		info$id  = c$id;
diff --git a/scripts/base/protocols/ssl/files.zeek b/scripts/base/protocols/ssl/files.zeek
index 52de1f5da6..d155825f2e 100644
--- a/scripts/base/protocols/ssl/files.zeek
+++ b/scripts/base/protocols/ssl/files.zeek
@@ -102,7 +102,7 @@ event file_sniff(f: fa_file, meta: fa_metadata) &priority=5
 	         || f$info$mime_type == "application/pkix-cert" ) )
 		return;
 
-	local c: connection &is_set;	# &is_set to help static analysis
+	local c: connection &is_assigned;	# to help static analysis
 
 	for ( cid, c in f$conns )
 		{
diff --git a/scripts/policy/protocols/ssl/log-hostcerts-only.zeek b/scripts/policy/protocols/ssl/log-hostcerts-only.zeek
index 52fc6b8b22..2019adfa6f 100644
--- a/scripts/policy/protocols/ssl/log-hostcerts-only.zeek
+++ b/scripts/policy/protocols/ssl/log-hostcerts-only.zeek
@@ -44,7 +44,7 @@ event file_sniff(f: fa_file, meta: fa_metadata) &priority=4
 		 || f$info$mime_type == "application/pkix-cert" ) )
 		return;
 
-	local c: connection &is_set;
+	local c: connection &is_assigned;
 
 	for ( cid, c in f$conns )
 		{
diff --git a/scripts/policy/protocols/ssl/validate-sct.zeek b/scripts/policy/protocols/ssl/validate-sct.zeek
index 8a7d38f353..796cd127a7 100644
--- a/scripts/policy/protocols/ssl/validate-sct.zeek
+++ b/scripts/policy/protocols/ssl/validate-sct.zeek
@@ -95,7 +95,7 @@ event x509_ocsp_ext_signed_certificate_timestamp(f: fa_file, version: count, log
 	if ( |f$conns| != 1 )
 		return;
 
-	local c: connection &is_set;
+	local c: connection &is_assigned;
 
 	for ( cid, c in f$conns )
 		{
diff --git a/src/Attr.cc b/src/Attr.cc
index 9ca5283715..0c134606fb 100644
--- a/src/Attr.cc
+++ b/src/Attr.cc
@@ -290,7 +290,7 @@ void Attributes::CheckAttr(Attr* a)
 	switch ( a->Tag() ) {
 	case ATTR_DEPRECATED:
 	case ATTR_REDEF:
-	case ATTR_IS_SET:
+	case ATTR_IS_ASSIGNED:
 		break;
 
 	case ATTR_OPTIONAL:
diff --git a/src/Attr.h b/src/Attr.h
index df8667dfb6..c63b0adacc 100644
--- a/src/Attr.h
+++ b/src/Attr.h
@@ -46,7 +46,7 @@ enum AttrTag {
 	ATTR_BROKER_STORE_ALLOW_COMPLEX, // for Broker store backed tables
 	ATTR_BACKEND, // for Broker store backed tables
 	ATTR_DEPRECATED,
-	ATTR_IS_SET, // to suppress warnings
+	ATTR_IS_ASSIGNED, // to suppress warnings
 	NUM_ATTRS // this item should always be last
 };
 
diff --git a/src/parse.y b/src/parse.y
index 6429d9250f..11c168541f 100644
--- a/src/parse.y
+++ b/src/parse.y
@@ -28,7 +28,7 @@
 %token TOK_ATTR_BROKER_STORE_ALLOW_COMPLEX TOK_ATTR_BACKEND
 %token TOK_ATTR_PRIORITY TOK_ATTR_LOG TOK_ATTR_ERROR_HANDLER
 %token TOK_ATTR_TYPE_COLUMN TOK_ATTR_DEPRECATED
-%token TOK_ATTR_IS_SET
+%token TOK_ATTR_IS_ASSIGNED
 
 %token TOK_DEBUG
 
@@ -1472,8 +1472,8 @@ attr:
 			{ $$ = new zeek::detail::Attr(zeek::detail::ATTR_OPTIONAL); }
 	|	TOK_ATTR_REDEF
 			{ $$ = new zeek::detail::Attr(zeek::detail::ATTR_REDEF); }
-	|	TOK_ATTR_IS_SET
-			{ $$ = new zeek::detail::Attr(zeek::detail::ATTR_IS_SET); }
+	|	TOK_ATTR_IS_ASSIGNED
+			{ $$ = new zeek::detail::Attr(zeek::detail::ATTR_IS_ASSIGNED); }
 	|	TOK_ATTR_ADD_FUNC '=' expr
 			{ $$ = new zeek::detail::Attr(zeek::detail::ATTR_ADD_FUNC, {zeek::AdoptRef{}, $3}); }
 	|	TOK_ATTR_DEL_FUNC '=' expr
diff --git a/src/scan.l b/src/scan.l
index 15777124d7..da512f4206 100644
--- a/src/scan.l
+++ b/src/scan.l
@@ -285,7 +285,7 @@ when	return TOK_WHEN;
 &expire_func	return TOK_ATTR_EXPIRE_FUNC;
 &log		return TOK_ATTR_LOG;
 &optional	return TOK_ATTR_OPTIONAL;
-&is_set		return TOK_ATTR_IS_SET;
+&is_assigned	return TOK_ATTR_IS_ASSIGNED;
 &priority	return TOK_ATTR_PRIORITY;
 &type_column	return TOK_ATTR_TYPE_COLUMN;
 &read_expire	return TOK_ATTR_EXPIRE_READ;
diff --git a/src/script_opt/GenRDs.cc b/src/script_opt/GenRDs.cc
index 3400d4d470..ddd3ebb54a 100644
--- a/src/script_opt/GenRDs.cc
+++ b/src/script_opt/GenRDs.cc
@@ -733,7 +733,7 @@ void RD_Decorate::CheckVar(const Expr* e, const ID* id, bool check_fields)
 		return;
 
 	if ( analysis_options.usage_issues > 0 &&
-	     ! mgr.HasPreMinRD(e, id) && ! id->GetAttr(ATTR_IS_SET) )
+	     ! mgr.HasPreMinRD(e, id) && ! id->GetAttr(ATTR_IS_ASSIGNED) )
 		e->Warn("possibly used without definition");
 
 	if ( check_fields && id->GetType()->Tag() == TYPE_RECORD )
@@ -921,7 +921,7 @@ TraversalCode RD_Decorate::PreExpr(const Expr* e)
 			{
 			auto r_def = mgr.GetExprDI(r);
 
-			if ( r_def && ! r_def->RootID()->GetAttr(ATTR_IS_SET) )
+			if ( r_def && ! r_def->RootID()->GetAttr(ATTR_IS_ASSIGNED) )
 				{
 				auto fn = f->FieldName();
 				auto field_rd = mgr.GetConstID_DI(r_def.get(), fn);
@@ -1243,7 +1243,7 @@ void RD_Decorate::CheckRecordRDs(std::shared_ptr<DefinitionItem> di,
 	CreateRecordRDs(di, dp, false, nullptr);
 
 	auto root_id = di->RootID();
-	if ( root_id->GetAttr(ATTR_IS_SET) )
+	if ( root_id->GetAttr(ATTR_IS_ASSIGNED) )
 		// No point checking for unset fields.
 		return;
 
@@ -1254,7 +1254,7 @@ void RD_Decorate::CheckRecordRDs(std::shared_ptr<DefinitionItem> di,
 		{
 		if ( rt->FieldHasAttr(i, ATTR_DEFAULT) ||
 		     rt->FieldHasAttr(i, ATTR_OPTIONAL) ||
-		     rt->FieldHasAttr(i, ATTR_IS_SET) )
+		     rt->FieldHasAttr(i, ATTR_IS_ASSIGNED) )
 			continue;
 
 		auto n_i = rt->FieldName(i);
diff --git a/testing/btest/language/uninitialized-local3.zeek b/testing/btest/language/uninitialized-local3.zeek
index a9623842d3..688628df6b 100644
--- a/testing/btest/language/uninitialized-local3.zeek
+++ b/testing/btest/language/uninitialized-local3.zeek
@@ -5,12 +5,12 @@ type r: record {
 	a: count;
 	b: count &optional;
 	c: count &default = 9;
-	d: string &is_set;
+	d: string &is_assigned;
 	e: string;
 };
 
 type r2: record {
-	no_worries: r &is_set;
+	no_worries: r &is_assigned;
 	worries: r;
 };
 
diff --git a/testing/btest/scripts/base/files/x509/signed_certificate_timestamp.test b/testing/btest/scripts/base/files/x509/signed_certificate_timestamp.test
index 10e2d98a14..c7645b9622 100644
--- a/testing/btest/scripts/base/files/x509/signed_certificate_timestamp.test
+++ b/testing/btest/scripts/base/files/x509/signed_certificate_timestamp.test
@@ -37,7 +37,7 @@ event x509_ocsp_ext_signed_certificate_timestamp(f: fa_file, version: count, log
 		if ( ! f$conns[cid]?$ssl )
 			return;
 
-		local c: connection &is_set;
+		local c: connection &is_assigned;
 		c = f$conns[cid];
 		}
 
diff --git a/testing/btest/scripts/base/files/x509/signed_certificate_timestamp_ocsp.test b/testing/btest/scripts/base/files/x509/signed_certificate_timestamp_ocsp.test
index 33de63f0b1..5211428817 100644
--- a/testing/btest/scripts/base/files/x509/signed_certificate_timestamp_ocsp.test
+++ b/testing/btest/scripts/base/files/x509/signed_certificate_timestamp_ocsp.test
@@ -20,7 +20,7 @@ event x509_ocsp_ext_signed_certificate_timestamp(f: fa_file, version: count, log
 		if ( ! f$conns[cid]?$ssl )
 			return;
 
-		local c: connection &is_set;
+		local c: connection &is_assigned;
 		c = f$conns[cid];
 		}