----------------------------------------------------
SQL keywords introduced in different server versions
----------------------------------------------------

Deviations from the standard:
 *  : keyword does not exist in the SQL:2016 specification and should be
      considered a non-standard language extention.
(1) : reserved word in SQL:2016, non-reserved in Firebird
(2) : non-reserved word in SQL:2016, reserved word in Firebird

Firebird 1.0
------------

  Added as reserved words:

    BREAK *
    CURRENT_ROLE
    CURRENT_USER
    DESCRIPTOR (2)
    FIRST (2)
    RECREATE *
    SKIP
    SUBSTRING

Firebird 1.5
------------

  Added as reserved words:

    BIGINT
    CASE
    CURRENT_CONNECTION *
    CURRENT_TRANSACTION *
    RELEASE
    ROW_COUNT
    SAVEPOINT

  Added as non-reserved words:

    COALESCE (1)
    DELETING *
    INSERTING *
    LAST
    LEAVE *
    LOCK *
    NULLIF (1)
    NULLS
    STATEMENT
    UPDATING *
    USING (1)

  Moved from reserved words to non-reserved:

    BREAK *
    DESCRIPTOR
    FIRST
    SKIP (1)
    SUBSTRING (1)

Firebird 2.0
------------

  Added as reserved words:

    BIT_LENGTH *
    BOTH
    CHAR_LENGTH
    CHARACTER_LENGTH
    CLOSE
    CROSS
    FETCH
    LEADING
    LOWER
    OCTET_LENGTH
    OPEN
    ROWS
    TRAILING
    TRIM

  Moved from non-reserved words to reserved:

    USING

  Added as non-reserved words:

    BACKUP *
    BLOCK *
    COLLATION
    COMMENT *
    DIFFERENCE *
    IIF *
    NEXT
    SCALAR_ARRAY *
    SEQUENCE
    RESTART
    RETURNING

  Moved from reserved words to non-reserved:

    ACTION
    CASCADE
    FREE_IT *
    RESTRICT
    ROLE
    TYPE
    WEEKDAY *
    YEARDAY *

  Removed reserved words:

    BASENAME *
    CACHE *
    CHECK_POINT_LEN *
    GROUP_COMMIT_WAIT *
    LOGFILE *
    LOG_BUF_SIZE *
    NUM_LOG_BUFS *
    RAW_PARTITIONS *

Firebird 2.1
------------

  Added as reserved words:

    CONNECT
    DISCONNECT
    GLOBAL
    INSENSITIVE
    RECURSIVE
    SENSITIVE
    START

  Added as non-reserved words:

    ABS (1)
    ACCENT *
    ACOS (1)
    ALWAYS
    ASCII_CHAR *
    ASCII_VAL *
    ASIN (1)
    ATAN (1)
    ATAN2 *
    BIN_AND *
    BIN_OR *
    BIN_SHL *
    BIN_SHR *
    BIN_XOR *
    CEIL (1)
    CEILING (1)
    COS (1)
    COSH (1)
    COT *
    DATEADD *
    DATEDIFF *
    DECODE *
    EXP (1)
    FLOOR (1)
    GEN_UUID *
    GENERATED
    HASH *
    LIST *
    LN (1)
    LOG (1)
    LOG10 (1)
    LPAD *
    MATCHED
    MATCHING *
    MAXVALUE
    MILLISECOND *
    MINVALUE
    MOD (1)
    OVERLAY (1)
    PAD
    PI *
    PLACING
    POWER (1)
    PRESERVE
    RAND *
    REPLACE *
    REVERSE *
    ROUND *
    RPAD *
    SIGN *
    SIN (1)
    SINH (1)
    SPACE
    SQRT (1)
    TAN (1)
    TANH (1)
    TEMPORARY
    TRUNC *
    WEEK *

Firebird 2.5
------------

  Added as reserved words:

    SIMILAR

  Added as non-reserved words:

    AUTONOMOUS *
    BIN_NOT *
    CALLER *
    CHAR_TO_UUID *
    COMMON *
    DATA
    FIRSTNAME *
    GRANTED
    LASTNAME *
    MIDDLENAME *
    MAPPING *
    OS_NAME *
    SOURCE
    TWO_PHASE *
    UUID_TO_CHAR *

Firebird 3.0
------------

  Added as reserved words:

    BOOLEAN
    CORR
    COVAR_POP
    COVAR_SAMP
    DETERMINISTIC
    FALSE
    OFFSET
    OVER
    RDB$RECORD_VERSION *
    REGR_AVGX
    REGR_AVGY
    REGR_COUNT
    REGR_INTERCEPT
    REGR_R2
    REGR_SLOPE
    REGR_SXX
    REGR_SXY
    REGR_SYY
    RETURN
    ROW
    SCROLL
    SQLSTATE
    STDDEV_POP
    STDDEV_SAMP
    TRUE
    UNKNOWN
    VAR_POP
    VAR_SAMP

  Moved from non-reserved words to reserved:

    DELETING *
    INSERTING *
    RDB$GET_CONTEXT *
    RDB$SET_CONTEXT *
    UPDATING *

  Added as non-reserved words:

    ABSOLUTE
    ACOSH *
    ASINH *
    ATANH *
    BODY *
    CONTINUE
    DDL *
    DECRYPT *
    DENSE_RANK (1)
    ENCRYPT *
    ENGINE *
    FIRST_VALUE (1)
    IDENTITY (1)
    INCREMENT
    LAST_VALUE (1)
    LAG (1)
    LEAD (1)
    LINGER *
    NAME
    NTH_VALUE (1)
    PACKAGE *
    PARTITION (1)
    PLUGIN *
    PRIOR
    RANK (1)
    RELATIVE
    ROW_NUMBER (1)
    SERVERWIDE *
    TAGS *
    TRUSTED *
    USAGE

Firebird 4.0
------------

  Added as reserved words:

    BINARY
    DECFLOAT
    LATERAL
    LOCAL
    LOCALTIME
    LOCALTIMESTAMP
    PUBLICATION *
    RDB$GET_TRANSACTION_CN *
    RDB$ERROR *
    RDB$ROLE_IN_USE *
    RDB$SYSTEM_PRIVILEGE *
    TIMEZONE_HOUR
    TIMEZONE_MINUTE
    UNBOUNDED (2)
    VARBINARY
    WINDOW
    WITHOUT

  Added as non-reserved words:

    BASE64_DECODE *
    BASE64_ENCODE *
    BIND *
    COMPARE_DECFLOAT *
    CONSISTENCY *
    COUNTER *
    CTR_BIG_ENDIAN *
    CTR_LENGTH *
    CTR_LITTLE_ENDIAN *
    CUME_DIST (1)
    DEFINER
    DISABLE *
    ENABLE *
    EXCESS *
    EXCLUDE
    EXTENDED *
    FIRST_DAY *
    FOLLOWING
    HEX_DECODE *
    HEX_ENCODE *
    IDLE *
    INVOKER
    IV *
    LAST_DAY *
    LEGACY *
    LPARAM *
    MAKE_DBKEY *
    MESSAGE *
    MODE *
    NATIVE *
    NORMALIZE_DECFLOAT *
    NTILE (1)
    NUMBER
    OTHERS
    OVERRIDING
    PERCENT_RANK (1)
    PRECEDING
    PRIVILEGE *
    QUANTIZE *
    RANGE (1)
    RESET *
    RSA_DECRYPT *
    RSA_ENCRYPT *
    RSA_PRIVATE *
    RSA_PUBLIC *
    RSA_SIGN *
    RSA_VERIFY *
    SALT_LENGTH *
    SECURITY
    SESSION
    SIGNATURE *
    SQL (1)
    SYSTEM (1)
    TIES
    TOTALORDER *
    TRAPS *
    ZONE