FIX Protocol Tag 123: GapFillFlag

Y in a Sequence Reset that fills a gap during a resend (gap fill mode). N or absent means reset mode, used for recovery from a serious error.

Tag number: 123
Data type: BOOLEAN
FIX versions: FIX 4.0 to 5.0 SP2 and FIXT 1.1
Used in: 1 message type

Tag 123 in each FIX version

Values and message usage as defined in a specific version.

Data type

BOOLEAN: Y for yes or N for no.

Valid values

2 enumerated values across all FIX versions.

Value	Meaning
N	No
Y	Yes

Example

123=N

Illustrative value. In a message, fields are separated by the SOH character (0x01), often shown as | or ^ in logs.

Decode a message with this tag

Message types that use tag 123

Sequence Reset 35=4

Covers every version from FIX 4.0 to 5.0 SP2, including fields reached through components and repeating groups. The version pages above show whether the tag is required in each message.

Field and message data comes from the QuickFIX data dictionaries for FIX 4.0 to 5.0 SP2 and FIXT 1.1, used under the QuickFIX Software License. This product includes software developed by quickfixengine.org (http://www.quickfixengine.org/). Enumerated value names are converted to plain text for reading.