+.. topic:: UDP
+
+ Tests which use any kind of UDP traffic (STL or ASTF profile).
+
+.. topic:: TCP
+
+ Tests which use any kind of TCP traffic (STL or ASTF profile).
+
+.. topic:: TREX
+
+ Tests which test trex traffic without any software DUTs in the traffic path.
+
+..
+ TODO: Should we define tags STL and ASTF?
+
+.. topic:: UDP_UDIR
+
+ Tests which use unidirectional UDP traffic (STL profile only).
+
+.. topic:: UDP_BIDIR
+
+ Tests which use bidirectional UDP traffic (STL profile only).
+
+.. topic:: UDP_CPS
+
+ Tests which measure connections per second on minimal UDP pseudoconnections.
+ This implies ASTF traffic profile is used.
+ This tag selects specific output processing in PAL.
+
+.. topic:: TCP_CPS
+
+ Tests which measure connections per second on empty TCP connections.
+ This implies ASTF traffic profile is used.
+ This tag selects specific output processing in PAL.
+
+.. topic:: TCP_RPS
+
+ Tests which measure requests per second on empty TCP connections.
+ This implies ASTF traffic profile is used.
+ This tag selects specific output processing in PAL.
+
+.. topic:: UDP_PPS
+
+ Tests which measure packets per second on lightweight UDP transactions.
+ This implies ASTF traffic profile is used.
+ This tag selects specific output processing in PAL.
+
+.. topic:: TCP_PPS
+
+ Tests which measure packets per second on lightweight TCP transactions.
+ This implies ASTF traffic profile is used.
+ This tag selects specific output processing in PAL.
+
+.. topic:: HTTP
+
+ Tests which use traffic formed of valid HTTP requests (and responses).
+
+..
+ TODO: Add HTTP tag to the current hoststack tests.
+ TODO: Document other tags already used by hoststack tests.
+
+.. topic:: LDP_NGINX
+
+ LDP NGINX is un-modified NGINX with VPP via LD_PRELOAD.
+
+.. topic:: NF_DENSITY
+
+ Performance tests that measure throughput of multiple VNF and CNF
+ service topologies at different service densities.
+
+NF Service Density Tags
+-----------------------
+
+.. topic:: CHAIN
+
+ NF service density tests with VNF or CNF service chain topology(ies).
+
+.. topic:: PIPE