Output drive and fan-out limits
The output stage is rated for 400µA source and 8mA sink. That sink current is enough to drive a standard TTL load or a couple of LS inputs, but it will not directly drive an LED or a relay coil without a buffer. If the downstream load pulls more than 8mA low, the output voltage rises above the guaranteed VOL level and the logic-low margin disappears. Keep the fan-out to ten 74LS loads or fewer, and verify the input current of whatever comes next.
For new designs, this part is a straightforward choice if the 74LS logic family and 5V supply are already in the BOM.