The `graphite_tag_sanitize_mode` option defines how we should sanitize the tag names and values. Possible values are `strict`, or `compatible`, with the default being `strict`.
When in `strict` mode Telegraf uses the same rules as metrics when not using tags.
When in `compatible` mode Telegraf allows more characters through, and is based on the Graphite specification:
>Tag names must have a length >= 1 and may contain any ascii characters except `;!^=`. Tag values must also have a length >= 1, they may contain any ascii characters except `;` and the first character must not be `~`. UTF-8 characters may work for names and values, but they are not well tested and it is not recommended to use non-ascii characters in metric names or tags. Metric names get indexed under the special tag name, if a metric name starts with one or multiple ~ they simply get removed from the derived tag value because the ~ character is not allowed to be in the first position of the tag value. If a metric name consists of no other characters than ~, then it is considered invalid and may get dropped.