From Halopedia, the Halo wiki
Flea++, as it has been named by Halo fans in reference to C++, is a programming and command line syntax seen in the I Love Bees alternate reality game. It is used by the SPDR and the Seeker (aka "Pious Flea"). The former's use of the language may imply that the language is used in other UNSC constructs.
The language includes several operators. An exclamation mark prefixed to a word indicates that the word is a command. An angle bracket (">") in the middle of a statement tends to denote a question or some uncertainty; two such brackets (">>") serve as a highly-context-sensitive operator denoting some association.
Note that some commands were used exclusively by the Seeker. Such commands may not be used by the UNSC.
The language has a large set of keywords, and makes use of various programming terms, which shall be explained here.
Commands and descriptors
In addition to regular commands, there are also command descriptors. Command descriptors occupy their own line, and take the form of a single word with a colon appended to it. Command descriptors describe the commands that follow them.
Here is a sample of Flea++ code, along with its fan-translated meaning. The code itself appears in an SPDR message announcing the Seeker's destruction. The sans-serif lines are commands used by the Seeker; the serif lines are the SPDR's commands.
grope: seeker > !attach Princess fail "msg: SPDR-5.14.3 evade evade evade !probe extern proc 1 rogue proc !bite rogue proc 1 recurse clean !splotch confidence 100
And now, the line-by-line translation.
Another message from the Seeker, found on the hacked ilovebees website, contains this code:
!init transmit proc !transmit truth Princess friends>>seeker friends
In this code block, the Seeker starts a process for a transmission program, and then attempts to transmit the truth. (It can be assumed that