The log should be in Cabrillo format. For more details, see Cabrillo File Format below.
The ADIF format is not accepted.
Be sure each line in the header begins with a key as shown below.
Check the header area of the log to be sure there are spaces after the colons and the keys are properly hyphenated.
The contest name in the log is CONTEST: A. VOLTA RTTY.
The entry category information is correct; See format below.
The time and date (UTC) of each QSO must be within the contest period and in the format below.
The first line in the log must be START-LOF-LOG and the last line in the log must be END-OF-LOG:
No special characters should be inserted between the RST EXCH and ZN fields.
Check the Cabrillo file header closely before submitting your log. Items may have been omitted or may be incomplete.

Cabrillo 3.0 field format
HEADER format

CALLSIGN: call
CATEGORY-OPERATOR: SINGLE-OP / MULTI-OP / CHECKLOG
CATEGORY-BAND: ALL / xxM - where xx = 10, 15, 20, 40, 80
CATEGORY-TIME: NULL (for 24 Hours) / 6H / 6 HOURS

QSO format

                                       ---------- info sent ---- ----- info rcvd ----------
        QSO: freq* mo |**date**| time |****call***| rst exch* zn |****call***| rst exch* zn  pts
        QSO: ***** ** yyyy-mm-dd nnnn ************* nnn ***** ** ************* nnn ***** **  ***
        QSO: 14109 RY 2021-05-08 1319 IK2LOL        599 0001  15 M0CHK         599 0117  14  003
        
Cabrillo 2.0 field format
HEADER format

CALLSIGN: call
CATEGORY: SINGLE-OP ALL / SINGLE-OP 6H / SINGLE-OP xxM - where xx = 10, 15, 20, 40, 80 / MULTI-OP / CHECKLOG

QSO format

                                         ---------- info sent ---- ----- info rcvd ----------
        QSO: freq* mo |**date**| time |****call***| rst exch* zn |****call***| rst exch* zn
        QSO: ***** ** yyyy-mm-dd nnnn ************* nnn ***** ** ************* nnn ***** **
        QSO: 14109 RY 2021-05-08 1319 IK2LOL        599 0001  15 M0CHK         599 0117  14