[Gil3075]

I think that every two digits represent a letter...

31 / 88 27 41 53, / 62 23 41 41 53 26
41 23 83 97 53 88 / 97 88 53 31 97
31 / 26 23 83 83 53 88, / 33 23 41 41 53 26
93 27 64 26 23 83 97 / 99 53 23 97 93 97

and it means that the whole thing is made of 14 different letters:

31 - probably A or I
88
27
41
53
62
23
26
83
97
33
93
64
99

5 of these must be aeiou, and additional 9 others

now what?