The Counter field in the Type 2 Entry format is used to differentiate different Subscribe Eventgroups to otherwise identical Eventgroups (i.e. same Service ID, same Instance ID, same Eventgroup ID, and same Major Version). The Counter field shall be reflected by the Server to the Subscribe Eventgroup Ack and Nack entries. 类型2 Entry格式中的Counter字段用于将Subscribe Eventgroup和其他相同的Eventgroup进行区分（即相同的 Service ID，相同的 Instance ID，相同的Eventgroup ID和相同的Major Version ）。 Counter字段应由服务器反映到Subscribe Eventgroup Ack和Nack条目。
If identical Consumed Eventgroups are configured with different Endpoints, then the SD shall use the Counter to differentiate the different Subscriptions. The value of the Counter can be determined by the implementation. 如果相同的Consumed Eventgroups配置了不同的Endpoint，则SD应使用Counter去区分不同的Subscription。 Counter的值可以由具体实现来确定。
Note注意: A width of 4 bits limits this to 16 different Subscriptions to the same Eventgroup. 4位宽度将此限制为同一个Eventgroup最多有16个不同的Subscription。
