Update existing routes:

GET /svn/:id

{
    "id": int,
    ...
    "settings": {
        "commit_rules": {
            "mandatory_reference": boolean,
            "allow_commit_message_change": boolean
        },
        "access_file": [
            "[/]",
            "* = ",
            "Contributors = r",
            "[/stuff]",
            "Contributors = rw"
        ],
        "immutable_tags": {
            "paths": [
                "/tags"
            ],
            "whitelist": [
                "/tags/moduleX"
            ]
        },
        "email_notifications": {
            [
                {
                    "path": "/trunk",
                    "user_groups": [
                        {
                            "id": "101_3",
                            "uri": "user_groups/101_3",
                            "label": "Project members"
                        },
                        UserGroupRepresentation
                    ],
                    "users": [
                        {
                            "id": 333,
                            "uri": "/users/333",
                            "username": "...",
                            ...
                        },
                        UserRepresentation
                    ],
                    "emails": [
                        "foo@example.com",
                        string
                    ]
                }
            ]
        }
    }
}

POST /svn

{
    ...
    "settings": {
        "commit_rules": {
            "mandatory_reference": boolean,
            "allow_commit_message_change": boolean
        },
        "access_file": [
            "[/]",
            "* = ",
            "Contributors = r",
            "[/stuff]",
            "Contributors = rw"
        ],
        "immutable_tags": {
            "paths": [
                "/tags"
            ],
            "whitelist": [
                "/tags/moduleX"
            ]
        },
        "email_notifications": {
            [
                {
                    "path": "/trunk",
                    "user_groups": [
                        {
                            "id": "101_3"
                        },
                        UserGroupRepresentation
                    ],
                    "users": [
                        {
                            "id": 333
                        },
                        UserRepresentation
                    ],
                    "emails": [
                        "foo@example.com",
                        string
                    ]
                }
            ]
        }
    }
}

• For both "user_groups" and "user" the key is the id but the whole Representation can be passed along (and will be ignored). This ease the REST call chaining.

PUT /svn/:id

{
    "id": int
    "settings": {
        "commit_rules": {
            "mandatory_reference": boolean,
            "allow_commit_message_change": boolean
        },
        "access_file": [
            "[/]",
            "* = ",
            "Contributors = r",
            "[/stuff]",
            "Contributors = rw"
        ],
        "immutable_tags": {
            "paths": [
                "/tags"
            ],
            "whitelist": [
                "/tags/moduleX"
            ]
        },
        "email_notifications": {
            [
                {
                    "path": "/trunk",
                    "user_groups": [
                        {
                            "id": "101_3",
                        },
                        UserGroupRepresentation
                    ],
                    "users": [
                        {
                            "id": 333,
                        },
                        UserRepresentation
                    ],
                    "emails": [
                        "foo@example.com",
                        string
                    ]
                }
            ]
        }
    }
}

• For both "user_groups" and "user" the key is the id but the whole Representation can be passed along (and will be ignored). This ease the REST call chaining.
• Changes are recorded in Project History