Ну да, не стандартизована. В стандратах EIA/TIA нету распиновок разъемов. Только сами интерфейсы стандартизованы. TIA/EIA-561
TIA/EIA-561 is a complete standard specifying a
non-synchronous DTE/DCE serial interface. It is a complete
standard specifying the function of the lines (Data, Timing &
Control) and a small 8 position connector (MJ8). This standard
references TIA/EIA-562 standard for line driver and
receiver requirements and characteristics. The standard
supports data rates up to 38.4 kbps.
В свою очередь
TIA/EIA-562
TIA/EIA-562 is a electrical standard which is very similar to
TIA/EIA-232-F, but supports higher data rates (64 kbps). It is
an electrical only standard, which is intended to be referenced
by complete standards, such as TIA/EIA-561.
TIA/EIA-562 specifies an unbalanced, unidirectional,
point-to-point interface. This standard supports
inter-operability with TIA/EIA-232-F devices. Figure 5 illustrates
a typical application, and Table 3 lists the major electrical
requirements.
Т.е. 561/562 от 232 отличаются только верхним пределом baudrate. А 561 от 562 наличием дополнительных сигналов квитирования с помощью которых реализуется handshake промеж DTE и DCE.