The following terms have a special meaning in Firebird 5.0 SQL. This lists all keywords, reserved and non-reserved.
!<
^<
^=
^>
,
:=
!=
!>
(
)
<
<=
<>
=
>
>=
||
~<
~=
~>
ABS
ABSOLUTE
ACCENT
ACOS
ACOSH
ACTION
ACTIVE
ADD
ADMIN
AFTER
ALL
ALTER
ALWAYS
AND
ANY
AS
ASC
ASCENDING
ASCII_CHAR
ASCII_VAL
ASIN
ASINH
AT
ATAN
ATAN2
ATANH
AUTO
AUTONOMOUS
AVG
BACKUP
BASE64_DECODE
BASE64_ENCODE
BEFORE
BEGIN
BETWEEN
BIGINT
BINARY
BIND
BIN_AND
BIN_NOT
BIN_OR
BIN_SHL
BIN_SHR
BIN_XOR
BIT_LENGTH
BLOB
BLOB_APPEND
BLOCK
BODY
BOOLEAN
BOTH
BREAK
BY
CALLER
CASCADE
CASE
CAST
CEIL
CEILING
CHAR
CHARACTER
CHARACTER_LENGTH
CHAR_LENGTH
CHAR_TO_UUID
CHECK
CLEAR
CLOSE
COALESCE
COLLATE
COLLATION
COLUMN
COMMENT
COMMIT
COMMITTED
COMMON
COMPARE_DECFLOAT
COMPUTED
CONDITIONAL
CONNECT
CONNECTIONS
CONSISTENCY
CONSTRAINT
CONTAINING
CONTINUE
CORR
COS
COSH
COT
COUNT
COUNTER
COVAR_POP
COVAR_SAMP
CREATE
CROSS
CRYPT_HASH
CSTRING
CTR_BIG_ENDIAN
CTR_LENGTH
CTR_LITTLE_ENDIAN
CUME_DIST
CURRENT
CURRENT_CONNECTION
CURRENT_DATE
CURRENT_ROLE
CURRENT_TIME
CURRENT_TIMESTAMP
CURRENT_TRANSACTION
CURRENT_USER
CURSOR
DATA
DATABASE
DATE
DATEADD
DATEDIFF
DAY
DDL
DEBUG
DEC
DECFLOAT
DECIMAL
DECLARE
DECODE
DECRYPT
DEFAULT
DEFINER
DELETE
DELETING
DENSE_RANK
DESC
DESCENDING
DESCRIPTOR
DETERMINISTIC
DIFFERENCE
DISABLE
DISCONNECT
DISTINCT
DO
DOMAIN
DOUBLE
DROP
ELSE
ENABLE
ENCRYPT
END
ENGINE
ENTRY_POINT
ESCAPE
EXCEPTION
EXCESS
EXCLUDE
EXECUTE
EXISTS
EXIT
EXP
EXTENDED
EXTERNAL
EXTRACT
FALSE
FETCH
FILE
FILTER
FIRST
FIRSTNAME
FIRST_DAY
FIRST_VALUE
FLOAT
FLOOR
FOLLOWING
FOR
FOREIGN
FREE_IT
FROM
FULL
FUNCTION
GDSCODE
GENERATED
GENERATOR
GEN_ID
GEN_UUID
GLOBAL
GRANT
GRANTED
GROUP
HASH
HAVING
HEX_DECODE
HEX_ENCODE
HOUR
IDENTITY
IDLE
IF
IGNORE
IIF
IN
INACTIVE
INCLUDE
INCREMENT
INDEX
INNER
INPUT_TYPE
INSENSITIVE
INSERT
INSERTING
INT
INT128
INTEGER
INTO
INVOKER
IS
ISOLATION
IV
JOIN
KEY
LAG
LAST
LASTNAME
LAST_DAY
LAST_VALUE
LATERAL
LEAD
LEADING
LEAVE
LEFT
LEGACY
LENGTH
LEVEL
LIFETIME
LIKE
LIMBO
LINGER
LIST
LN
LOCAL
LOCALTIME
LOCALTIMESTAMP
LOCK
LOCKED
LOG
LOG10
LONG
LOWER
LPAD
LPARAM
MAKE_DBKEY
MANUAL
MAPPING
MATCHED
MATCHING
MAX
MAXVALUE
MERGE
MESSAGE
MIDDLENAME
MILLISECOND
MIN
MINUTE
MINVALUE
MOD
MODE
MODULE_NAME
MONTH
NAME
NAMES
NATIONAL
NATIVE
NATURAL
NCHAR
NEXT
NO
NORMALIZE_DECFLOAT
NOT
NTH_VALUE
NTILE
NULL
NULLIF
NULLS
NUMBER
NUMERIC
OCTET_LENGTH
OF
OFFSET
OLDEST
ON
ONLY
OPEN
OPTIMIZE
OPTION
OR
ORDER
OS_NAME
OTHERS
OUTER
OUTPUT_TYPE
OVER
OVERFLOW
OVERLAY
OVERRIDING
PACKAGE
PAD
PAGE
PAGES
PAGE_SIZE
PARAMETER
PARTITION
PASSWORD
PERCENT_RANK
PI
PKCS_1_5
PLACING
PLAN
PLUGIN
POOL
POSITION
POST_EVENT
POWER
PRECEDING
PRECISION
PRESERVE
PRIMARY
PRIOR
PRIVILEGE
PRIVILEGES
PROCEDURE
PROTECTED
PUBLICATION
QUANTIZE
QUARTER
RAND
RANGE
RANK
RDB$DB_KEY
RDB$ERROR
RDB$GET_CONTEXT
RDB$GET_TRANSACTION_CN
RDB$RECORD_VERSION
RDB$ROLE_IN_USE
RDB$SET_CONTEXT
RDB$SYSTEM_PRIVILEGE
READ
REAL
RECORD_VERSION
RECREATE
RECURSIVE
REFERENCES
REGR_AVGX
REGR_AVGY
REGR_COUNT
REGR_INTERCEPT
REGR_R2
REGR_SLOPE
REGR_SXX
REGR_SXY
REGR_SYY
RELATIVE
RELEASE
REPLACE
REQUESTS
RESERV
RESERVING
RESET
RESETTING
RESTART
RESTRICT
RETAIN
RETURN
RETURNING
RETURNING_VALUES
RETURNS
REVERSE
REVOKE
RIGHT
ROLE
ROLLBACK
ROUND
ROW
ROWS
ROW_COUNT
ROW_NUMBER
RPAD
RSA_DECRYPT
RSA_ENCRYPT
RSA_PRIVATE
RSA_PUBLIC
RSA_SIGN_HASH
RSA_VERIFY_HASH
SALT_LENGTH
SAVEPOINT
SCALAR_ARRAY
SCHEMA
SCROLL
SECOND
SECURITY
SEGMENT
SELECT
SENSITIVE
SEQUENCE
SERVERWIDE
SESSION
SET
SHADOW
SHARED
SIGN
SIGNATURE
SIMILAR
SIN
SINGULAR
SINH
SIZE
SKIP
SMALLINT
SNAPSHOT
SOME
SORT
SOURCE
SPACE
SQL
SQLCODE
SQLSTATE
SQRT
STABILITY
START
STARTING
STARTS
STATEMENT
STATISTICS
STDDEV_POP
STDDEV_SAMP
SUBSTRING
SUB_TYPE
SUM
SUSPEND
SYSTEM
TABLE
TAGS
TAN
TANH
TARGET
TEMPORARY
THEN
TIES
TIME
TIMEOUT
TIMESTAMP
TIMEZONE_HOUR
TIMEZONE_MINUTE
TIMEZONE_NAME
TO
TOTALORDER
TRAILING
TRANSACTION
TRAPS
TRIGGER
TRIM
TRUE
TRUNC
TRUSTED
TWO_PHASE
TYPE
UNBOUNDED
UNCOMMITTED
UNDO
UNICODE_CHAR
UNICODE_VAL
UNION
UNIQUE
UNKNOWN
UPDATE
UPDATING
UPPER
USAGE
USER
USING
UUID_TO_CHAR
VALUE
VALUES
VARBINARY
VARCHAR
VARIABLE
VARYING
VAR_POP
VAR_SAMP
VIEW
WAIT
WEEK
WEEKDAY
WHEN
WHERE
WHILE
WINDOW
WITH
WITHOUT
WORK
WRITE
YEAR
YEARDAY
ZONE