The syntax is:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>fileTypes</key>
<array>
<string>testlang</string>
</array>
<key>name</key>
<string>testlang</string>
<key>patterns</key>
<array>
<dict>
<key>include</key>
<string>#indentedVerbatimOp</string>
</dict>
</array>
<key>repository</key>
<dict>
<key>indentedVerbatimOp</key>
<dict>
<key>begin</key>
<string>^([ \t]*)(?=(.*?)\|$)</string>
<key>end</key>
<string>^(?!\1[ \t])(?=[ \t]*\S)</string>
<key>name</key>
<string>string.unquoted.verbatim.youki</string>
</dict>
</dict>
<key>scopeName</key>
<string>text.testlang</string>
<key>uuid</key>
<string>159375af-d9b4-448c-a9da-d235eadf3556</string>
</dict>
</plist>
It matches indented block with a leading line ending with a bar (|). I've found that Code cannot match the block's ending, which is zero-width:

Sublime can match it perfectly:

If I add some character to the end tag then Code works again:
<key>end</key>
<string>^(?!\1[ \t])(?=[ \t]*\S)xx</string>

The syntax is:
It matches indented block with a leading line ending with a bar (

|). I've found that Code cannot match the block's ending, which is zero-width:Sublime can match it perfectly:

If I add some character to the end tag then Code works again: