This read-only Counter32 counts residual bit errors detected on incoming HDLC-like frames for a particular interface, i.e., frames whose bit length didn't align on a proper byte boundary after decoding. An admin uses this counter as a sign of framing or clocking problems on the link, since a non-byte-aligned frame usually indicates bit-level corruption in transit. For example, a rising residual-bit-error count alongside a marginal serial line would suggest a clocking mismatch between the two HDLC endpoints.