I found this tip from forum discussing about Oracle’s reserved words. You can use it to quickly view reserved words for both SQL and PL/SQL.
SQL> help reserved RESERVED WORDS (PL/SQL) ----------------------- PL/SQL Reserved Words have special meaning in PL/SQL, and may not be used for identifier names (unless enclosed in "quotes"). An asterisk (*) indicates words are also SQL Reserved Words. ALL* DESC* JAVA PACKAGE SUBTYPE ALTER* DISTINCT* LEVEL* PARTITION SUCCESSFUL* AND* DO LIKE* PCTFREE* SUM ANY* DROP* LIMITED PLS_INTEGER SYNONYM* ARRAY ELSE* LOCK* POSITIVE SYSDATE* AS* ELSIF LONG* POSITIVEN TABLE* ASC* END LOOP PRAGMA THEN* AT EXCEPTION MAX PRIOR* TIME AUTHID EXCLUSIVE* MIN PRIVATE TIMESTAMP AVG EXECUTE MINUS* PROCEDURE TIMEZONE_ABBR BEGIN EXISTS* MINUTE PUBLIC* TIMEZONE_HOUR BETWEEN* EXIT MLSLABEL* RAISE TIMEZONE_MINUTE BINARY_INTEGER EXTENDS MOD RANGE TIMEZONE_REGION BODY EXTRACT MODE* RAW* TO* BOOLEAN FALSE MONTH REAL TRIGGER* BULK FETCH NATURAL RECORD TRUE BY* FLOAT* NATURALN REF TYPE CHAR* FOR* NEW RELEASE UI CHAR_BASE FORALL NEXTVAL RETURN UNION* CHECK* FROM* NOCOPY REVERSE UNIQUE* CLOSE FUNCTION NOT* ROLLBACK UPDATE* CLUSTER* GOTO NOWAIT* ROW* USE COALESCE GROUP* NULL* ROWID* USER* COLLECT HAVING* NULLIF ROWNUM* VALIDATE* COMMENT* HEAP NUMBER* ROWTYPE VALUES* COMMIT HOUR NUMBER_BASE SAVEPOINT VARCHAR* COMPRESS* IF OCIROWID SECOND VARCHAR2* CONNECT* IMMEDIATE* OF* SELECT* VARIANCE CONSTANT IN* ON* SEPERATE VIEW* CREATE* INDEX* OPAQUE SET* WHEN CURRENT* INDICATOR OPEN SHARE* WHENEVER* CURRVAL INSERT* OPERATOR SMALLINT* WHERE* CURSOR INTEGER* OPTION* SPACE WHILE DATE* INTERFACE OR* SQL WITH* DAY INTERSECT* ORDER* SQLCODE WORK DECIMAL* INTERVAL ORGANIZATION SQLERRM WRITE DECLARE INTO* OTHERS START* YEAR DEFAULT* IS* OUT STDDEV ZONE DELETE* ISOLATION RESERVED WORDS (SQL) -------------------- SQL Reserved Words have special meaning in SQL, and may not be used for identifier names unless enclosed in "quotes". An asterisk (*) indicates words are also ANSI Reserved Words. Oracle prefixes implicitly generated schema object and subobject names with "SYS_". To avoid name resolution conflict, Oracle discourages you from prefixing your schema object and subobject names with "SYS_". ACCESS DEFAULT* INTEGER* ONLINE START ADD* DELETE* INTERSECT* OPTION* SUCCESSFUL ALL* DESC* INTO* OR* SYNONYM ALTER* DISTINCT* IS* ORDER* SYSDATE AND* DROP* LEVEL* PCTFREE TABLE* ANY* ELSE* LIKE* PRIOR* THEN* AS* EXCLUSIVE LOCK PRIVILEGES* TO* ASC* EXISTS LONG PUBLIC* TRIGGER AUDIT FILE MAXEXTENTS RAW UID BETWEEN* FLOAT* MINUS RENAME UNION* BY* FOR* MLSLABEL RESOURCE UNIQUE* CHAR* FROM* MODE REVOKE* UPDATE* CHECK* GRANT* MODIFY ROW USER* CLUSTER GROUP* NOAUDIT ROWID VALIDATE COLUMN HAVING* NOCOMPRESS ROWNUM VALUES* COMMENT IDENTIFIED NOT* ROWS* VARCHAR* COMPRESS IMMEDIATE* NOWAIT SELECT* VARCHAR2 CONNECT* IN* NULL* SESSION* VIEW* CREATE* INCREMENT NUMBER SET* WHENEVER* CURRENT* INDEX OF* SHARE WHERE DATE* INITIAL OFFLINE SIZE* WITH* DECIMAL* INSERT* ON* SMALLINT*
