= : in the flow context = It's not clear what is the best solution: 1. Forbid ':' for plain scalars in the flow context and use it to separate keys from values. his syntax is more Python-compatible. For instance, it allows {{{ {1:2,2:3,3:5,4:7,5:11,6:13,7:17,8:23} # prime numbers }}} 2. Allow ':' for plain scalars in the flow context provided it's not followed by a whitespace. Require ': ' to separate keys from values. This will allow unquoted time values and URLs in the flow context. For instance, {{{ [12:45, http://pyyaml.org/] # Time and URL }}} What do you think? '''Please leave an excerpt of your document which produced an error here, in the wiki page.''' presentation: {type: textarea_tag, params: rich=true tinymce_options=width:500 } this is a problem for me, please observe: {{{ found unexpected ':' in "", line 3, column 14: url: http://localhost/ }}} Here's another real-world example: {{{ dhcp: [ { group: linux_i386X, mac: 99:19:b9:fa:37:99, }, ] }}} I would definitely agree for the colon-space solution (it fixes these examples, but not, I suppose, every issue.) Yet another example: {{{ found unexpected ':' in "", line 1, column 11: urls: [ftp://ftp.cdrom.com/] }}} It would make sense to require ': ' when parsing a value - if you see a:b when parsing a value, you should treat that as the string "a:b". When parsing a key-value in a mapping, it should be possible to allow either url:http://pyyaml.org/ (no space) or url: http://pyyaml.org/ as you know from context that you're expecting a : to terminate a key. Of course, colons in keys are pathological and should not be tolerated ;-) Solution #1 may be natural for Python but not for other languages. Since YAML should stay language-neutral solution #2 would meet much more expectations. Example from Polyglot Maven: {{{ distributionManagement: site: { id: site, url: "http://www.apache.org" } repository: { id: releases, name: releases, url: "http://maven.sonatype.org/releases" } snapshotRepository: { id: snapshots, name: snapshots, url: "http://maven.sonatype.org/snapshots" } }}} Another example (from the Ruby world): {{{ Psych::SyntaxError: (): couldn't parse YAML at line 0 column 10 }}} and the source document: {{{ order: [ :year, :month, :day ] }}} Another real world example: {{{ {created_at: 2011-03-04T15:58:25Z} }}} Which was reported here[http://redmine.ruby-lang.org/issues/4479].