There are many different variants of the ARM architecture and implementations that have evolved over time. The notation can be confusing. For instance, arm7 and armv7, are completely different. The first is a CPU implementation; the second is a CPU architecture. The architecture, also called a family, is a set of machine instructions (or ISA for instruction set architecture) that are generally compatible. See: Wikipedia's list of ARM microarchitectures for more.
Other CPU specific tags exist, such as cortex-m3. Often those posts apply to other cortex-m CPUs and/or the difference between the versions is important to understand. Also newer future CPUs may extend a specific CPU and questions in that tag maybe relevant.
If you are only posting to the tag arm try to give some specifics about the system you are using.