vim - What is the reason that Ctrl+I and Tab keys send same codes? -

does can explain reason ctrl+i , tab keys send same code?
figure out it's because of "historical reasons".

for example, fact can affect on behavior of vim bindings in question.

i think has how tab encoded in ascii.

if @ ascii table , @ man page ascii (copied below)

oct   dec   hex   char                        oct   dec   hex   char ──────────────────────────────────────────────────────────────────────── 000   0     00    nul '\0'                    100   64    40    @    001   1     01    soh (start of heading)      101   65    41       002   2     02    stx (start of text)         102   66    42    b    003   3     03    etx (end of text)           103   67    43    c    004   4     04    eot (end of transmission)   104   68    44    d    005   5     05    enq (enquiry)               105   69    45    e    006   6     06    ack (acknowledge)           106   70    46    f    007   7     07    bel '\a' (bell)             107   71    47    g    010   8     08    bs  '\b' (backspace)        110   72    48    h    011   9     09    ht  '\t' (horizontal tab)   111   73    49       012   10    0a    lf  '\n' (new line)         112   74    4a    j    013   11    0b    vt  '\v' (vertical tab)     113   75    4b    k    014   12    0c    ff  '\f' (form feed)        114   76    4c    l    015   13    0d    cr  '\r' (carriage ret)     115   77    4d    m    

we can see tab 9th character (in decimal) in ascii character set. each 1 of non printing characters can typed using control , ith letter in alphabet. since 9th letter in alphabet <c-i> tab. why carriage returns show ^m.

as why vim treats them same. hold on long time ago when using control keys purpose important.