Keywords are also part of the language. They have a special meaning when used in the proper context, but they are not reserved for Firebird’s own and exclusive use. You can use them as identifiers without double-quoting.

    Full list of reserved words in Firebird 2.5:

    Keywords

    The following terms have a special meaning in Firebird 2.5 DSQL. Some of them are also reserved words, others are not.

    !<

    ^<

    ^=

    ^>

    ,

    !=

    !>

    )

    <

    <>

    =

    >

    >=

    ||

    ~<

    ~=

    ~>

    ABS

    ACCENT

    ACOS

    ACTION

    ACTIVE

    ADD

    ADMIN

    AFTER

    ALL

    ALTER

    ALWAYS

    AND

    ANY

    AS

    ASC

    ASCENDING

    ASCII_CHAR

    ASCII_VAL

    ASIN

    AT

    ATAN

    ATAN2

    AUTO

    AUTONOMOUS

    AVG

    BACKUP

    BEFORE

    BEGIN

    BETWEEN

    BIGINT

    BIN_AND

    BIN_NOT

    BIN_OR

    BIN_SHL

    BIN_SHR

    BIN_XOR

    BIT_LENGTH

    BLOB

    BLOCK

    BOTH

    BREAK

    BY

    CALLER

    CASCADE

    CASE

    CAST

    CEIL

    CEILING

    CHAR

    CHAR_LENGTH

    CHAR_TO_UUID

    CHARACTER

    CHARACTER_LENGTH

    CHECK

    CLOSE

    COALESCE

    COLLATE

    COLLATION

    COLUMN

    COMMENT

    COMMIT

    COMMITTED

    COMMON

    COMPUTED

    CONDITIONAL

    CONNECT

    CONSTRAINT

    CONTAINING

    COS

    COSH

    COT

    COUNT

    CREATE

    CROSS

    CSTRING

    CURRENT

    CURRENT_CONNECTION

    CURRENT_DATE

    CURRENT_ROLE

    CURRENT_TIME

    CURRENT_TIMESTAMP

    CURRENT_TRANSACTION

    CURRENT_USER

    CURSOR

    DATA

    DATABASE

    DATE

    DATEADD

    DATEDIFF

    DAY

    DEC

    DECIMAL

    DECLARE

    DECODE

    DEFAULT

    DELETE

    DELETING

    DESC

    DESCENDING

    DESCRIPTOR

    DIFFERENCE

    DISCONNECT

    DISTINCT

    DO

    DOMAIN

    DOUBLE

    DROP

    ELSE

    END

    ENTRY_POINT

    ESCAPE

    EXCEPTION

    EXECUTE

    EXISTS

    EXIT

    EXP

    EXTERNAL

    EXTRACT

    FETCH

    FILE

    FILTER

    FIRST

    FIRSTNAME

    FLOAT

    FLOOR

    FOR

    FOREIGN

    FREE_IT

    FROM

    FULL

    FUNCTION

    GDSCODE

    GEN_ID

    GEN_UUID

    GENERATED

    GENERATOR

    GLOBAL

    GRANT

    GRANTED

    GROUP

    HASH

    HAVING

    HOUR

    IF

    IGNORE

    IIF

    IN

    INACTIVE

    INDEX

    INNER

    INPUT_TYPE

    INSENSITIVE

    INSERT

    INSERTING

    INT

    INTEGER

    INTO

    IS

    ISOLATION

    JOIN

    KEY

    LAST

    LASTNAME

    LEADING

    LEAVE

    LEVEL

    LIKE

    LIMBO

    LIST

    LN

    LOCK

    LOG

    LOG10

    LONG

    LOWER

    LPAD

    MANUAL

    MAPPING

    MATCHED

    MATCHING

    MAX

    MAXIMUM_SEGMENT

    MAXVALUE

    MERGE

    MIDDLENAME

    MILLISECOND

    MIN

    MINUTE

    MINVALUE

    MOD

    MODULE_NAME

    MONTH

    NAMES

    NATIONAL

    NATURAL

    NCHAR

    NEXT

    NO

    NOT

    NULL

    NULLIF

    NULLS

    NUMERIC

    OCTET_LENGTH

    OF

    ON

    ONLY

    OPEN

    OPTION

    OR

    ORDER

    OS_NAME

    OUTER

    OUTPUT_TYPE

    OVER

    OVERFLOW

    OVERLAY

    PAD

    PAGE

    PAGE_SIZE

    PAGES

    PARAMETER

    PASSWORD

    PI

    PLACING

    PLAN

    POSITION

    POST_EVENT

    POWER

    PRECISION

    PRESERVE

    PRIMARY

    PRIVILEGES

    PROCEDURE

    PROTECTED

    RAND

    RDB$DB_KEY

    READ

    REAL

    RECORD_VERSION

    RECREATE

    RECURSIVE

    REFERENCES

    RELEASE

    REPLACE

    REQUESTS

    RESERV

    RESERVING

    RESTART

    RESTRICT

    RETAIN

    RETURNING

    RETURNING_VALUES

    RETURNS

    REVERSE

    REVOKE

    RIGHT

    ROLE

    ROLLBACK

    ROUND

    ROW_COUNT

    ROW_NUMBER

    ROWS

    RPAD

    SAVEPOINT

    SCALAR_ARRAY

    SCHEMA

    SECOND

    SEGMENT

    SELECT

    SENSITIVE

    SEQUENCE

    SET

    SHADOW

    SHARED

    SIGN

    SIMILAR

    SIN

    SINGULAR

    SINH

    SIZE

    SKIP

    SMALLINT

    SNAPSHOT

    SOME

    SORT

    SOURCE

    SPACE

    SQLCODE

    SQLSTATE (2.5.1)

    SQRT

    STABILITY

    START

    STARTING

    STARTS

    STATEMENT

    STATISTICS

    SUB_TYPE

    SUBSTRING

    SUM

    SUSPEND

    TABLE

    TAN

    TANH

    TEMPORARY

    THEN

    TIME

    TIMEOUT

    TIMESTAMP

    TO

    TRAILING

    TRANSACTION

    TRIGGER

    TRIM

    TRUNC

    TWO_PHASE

    TYPE

    UNCOMMITTED

    UNDO

    UNION

    UNIQUE

    UPDATE

    UPDATING

    UPPER

    USER

    USING

    UUID_TO_CHAR

    VALUE

    VALUES

    VARCHAR

    VARIABLE

    VARYING

    VIEW

    WAIT

    WEEK

    WEEKDAY

    WHEN

    WHERE

    WHILE

    WITH

    WORK

    WRITE