** Bug
* [PHPC-348] - Check for errors after calling bson_to_zval()
* [PHPC-889] - BSON decoding errors for Javascript scopes only thrown at access time
* [PHPC-1446] - Always enable TLS when any TLS option is specified
* [PHPC-1453] - SRV record lookup fails if DNS response exceeds 1024 characters
* [PHPC-1520] - Windows compiler warnings building extension with libmongocrypt
* [PHPC-1526] - Forking session test has intermittent failures on SHARDED_CLUSTER_RS
* [PHPC-1540] - Investigate segmentation fault when using keyVaultClient in AutoEncryptionOpts

** Epic
* [PHPC-1293] - Support Client-side Field Level Encryption (FLE)

** New Feature
* [PHPC-1230] - Support object cloning for BSON classes
* [PHPC-1462] - Support ability to pass hint to update
* [PHPC-1491] - Add ReadPreference::getModeString
* [PHPC-1496] - Support compiling with libmongocrypt
* [PHPC-1497] - Introduce new configure switch to use system libraries
* [PHPC-1498] - Handle autoEncryptionOpts in MongoDB\Driver\Manager
* [PHPC-1499] - Add clientEncryption API
* [PHPC-1500] - Change serialisation of objects for client hash
* [PHPC-1539] - Create new exception classes for FLE

** Task
* [PHPC-952] - Refactor BSON type initiators for unserialization visitors
* [PHPC-1002] - Test regularly with C Driver release or release candidate
* [PHPC-1073] - Remove superfluous php_array_exists calls where possible
* [PHPC-1074] - Refactor php_phongo_bson_state struct initialization for debug output
* [PHPC-1269] - Document that BulkWrite instances may only be executed once
* [PHPC-1279] - Improve documentation for Cursor::isDead()
* [PHPC-1312] - Advise users to use 64-bit environments if possible
* [PHPC-1314] - Document that users may need to copy libsasl.dll to lib path for Windows installs
* [PHPC-1343] - Add test to catch inaccessible server when running tests
* [PHPC-1372] - Re-enable ARM64 builds in Evergreen matrix
* [PHPC-1424] - Inform users that mongodb.debug output contains sensitive information
* [PHPC-1426] - Update stubs for PhpStorm
* [PHPC-1430] - Deprecate obsolete driver options
* [PHPC-1438] - Expose more precise session state
* [PHPC-1445] - Make find commands for collecting libmongoc sources portable between Linux and macOS
* [PHPC-1449] - Resync bson-corpus array.json to fix duplicate test names
* [PHPC-1450] - Document rules by which TLS is implicitly enabled
* [PHPC-1461] - Remove Community zSeries From 4.0 testing
* [PHPC-1470] - Remove unnecessary timezone settings in tests
* [PHPC-1471] - Clean up reference handling in Javascript scope serialisation
* [PHPC-1472] - Prevent multiple exceptions from being thrown during manager serialisation
* [PHPC-1492] - Remove conditional EXPECTF patterns in UTCDateTime tests
* [PHPC-1532] - Document client-side encryption functionality
* [PHPC-1546] - Ensure Windows builds enable SASL and FLE

** Improvement
* [PHPC-870] - Consider using ZEND_HASH_FOREACH indirect macros for iteration
* [PHPC-966] - Explicitly initialize fields for internal class structs
* [PHPC-991] - Handle duplicates in URI options array
* [PHPC-1274] - Reset libmongoc client after forking to avoid interacting with parent resources in child processes
* [PHPC-1281] - Serialization support for ReadConcern, ReadPreference, and WriteConcern
* [PHPC-1284] - Driver session pools must be cleared after forking
* [PHPC-1347] - Do not allow empty string for replicaSet
* [PHPC-1391] - Prohibit starting a transaction for maxWireVersion < 7
* [PHPC-1411] - Accept 64-bit integers for wTimeoutMS
* [PHPC-1418] - Test PHP 7.3 in Evergreen
* [PHPC-1439] - Expose transaction options on session object
* [PHPC-1459] - Add serialisation support for CursorId
* [PHPC-1521] - Only warn in config.w32 if SASL is enabled but not available
* [PHPC-1545] - Require object or array type for "kmsProviders" option