From: serilog/serilog-extensions-logging-file#7

When Serilog renders data, it uses a JSON-like representation, so strings end up "like this" while numbers are 123 and arrays [1, 2, 3] etc.

(Personal note - I can see the downside for some, but I still love this feature as it makes clear that there's more type information behind the scenes, when you can't use a sink with structured data support.)

In some cases, especially when trying to match legacy file output, it'd be nice to switch this off and just pretend we're a fancy string.Format(). Opting out at the level of individual tokens ({0:l}) doesn't really achieve what's desired here. It'd be nicer to override the rendering at a higher level.

One option for achieving this would be to modify MessageTemplateTextFormatter's handling of {Message} so that the :l is applied to the tokens within the message; e.g.:

"{Timestamp:o} {RequestId,13} [{Level:u3}] {Message:l} ({EventId:x8}){NewLine}{Exception}"

Implementation strategy needs some investigation, but doesn't seem like it will be too complicated.