Your dev would need to get their head round the SecRule syntax – but here are the two SecRule statements that make up the chain for rule 340464. As I say, though, we are dropping this ruleset soon, so it may be that it ceases to be an issue for you and more people find a different ruleset to use.
SecRule ARGS|!ARGS:/banner/|!ARGS:/option/|!ARGS:/stream/|!ARGS:/analytics_code/|!ARGS:/endpoint/|!ARGS:_local|!ARGS:lookup|!ARGS:/hostname/|!ARGS:/cdn/|!ARGS:/^ad/|!ARGS:/image/|!ARGS:/target/|!ARGS:shrbase|!ARGS:facebook|!ARGS:/twitter/|!ARGS:/facebook/|!ARGS:/pinterest/|!ARGS:youtube|!ARGS:myspace|!ARGS:form|!ARGS:/logo/|!ARGS:/img/|!ARGS:unsubscribe|!ARGS:/^dest_to/|!ARGS:/rss/|!ARGS:/lm_slide/|!ARGS:/feed/|!ARGS:/footer/|!ARGS:/^jsfiles/|!ARGS:/include/|!ARGS:/pagination/|!ARGS:/link/|!ARGS:/image/|!ARGS:/path/|!ARGS:/page/|!ARGS:field_b|!ARGS:/refer/|!ARGS:/^gbu0_/|!ARGS:/site/|!ARGS:/button/|!ARGS:guestbookLink|!ARGS:xmlpath|!ARGS:/^update/|!ARGS:/^woo_ad/|!ARGS:act_filepath|!ARGS:/domain/|!ARGS:opphomepage|!ARGS:echi_google_analytics|!ARGS:/^echi_block_/|!ARGS:/^echi_ad/|!ARGS:/icon/|!ARGS:descripcion|!ARGS:xcont_priv|!ARGS:/comments/|!ARGS:email|!ARGS:/video/|!ARGS:hometext|!ARGS:/text/|!ARGS:web|!ARGS:/^config/|!ARGS:/^g2_manualpath/|!ARGS:/^sDescription/|!ARGS:hidepost_content_text|!ARGS:sText|!ARGS:sfhome|!ARGS:homepage|!ARGS:field_3_name|!ARGS:cforms_cmsg|!ARGS:bcontent|!ARGS:form_location|!ARGS:footer|!ARGS:field_4_name|!ARGS:cforms_redirect_page|!ARGS:cforms_action_page|!ARGS:ecards_more_pic_target|!ARGS:message|!ARGS:/^xfoot/|!ARGS:/^rss/|!ARGS:/rss$/|!ARGS:/^FCKeditor/|!ARGS:/url/|!ARGS:/redirect/|!ARGS:/page/|!ARGS:content|!ARGS:/linkedin/|!ARGS:outbound|!ARGS:out|!ARGS:/twitter/|!ARGS:/^field/|!ARGS:/button/|!ARGS:/facebook/|!ARGS:/pinterest/|!ARGS:/youtube/|!ARGS:/affredir/|!ARGS:helpbox|!ARGS:return|!ARGS:comment|!ARGS:basehref|!ARGS:redirect|!ARGS:oaparams|!ARGS:loc|!ARGS:resource|!ARGS:thelink|!ARGS:params[altTag]|!ARGS:filecontent|!ARGS:inc|!ARGS:link|!ARGS:fck_body|!ARGS:fck_brief|!ARGS:introtext|!ARGS:resource_box|!ARGS:areaContent2|!ARGS:ref|!ARGS:userpicpersonal|!ARGS:body|!ARGS:linkdescr|!ARGS:Post|!ARGS:last_msg|!ARGS:params[link]|!ARGS:texty|!ARGS:params[request_url]|!ARGS:pay_list_type|!ARGS:FULL_URL|!ARGS:HOMEPAGE_URL|!ARGS:ATTACHMENTS_URL|!ARGS:templatePath|!ARGS:fulltext|!ARGS:stories_cat|!ARGS:sUrl|!ARGS:config_helpurl|!ARGS:website_link|!ARGS:view|!ARGS:redirect_to|!ARGS:return_link_url|!ARGS:oldmsg|!ARGS:lk_url|!ARGS:config[latestNewsRRS]|!ARGS:sponsor|!ARGS:config[ftp_server]|!ARGS:listViewerCode|!ARGS:/element/|!ARGS:/google/|!ARGS:courier_tracking|!ARGS:/field_id/|!ARGS:/social_profile/ "^(?:ogg|gopher|data|php|zlib|(?:ht|f)tps?):/" "chain,t:none,t:urlDecodeUni,t:base64Decode,t:hexDecode,t:htmlEntityDecode,t:lowercase,multimatch,id:340464,rev:53,severity:2,msg:'Atomicorp.com UNSUPPORTED DELAYED Rules: Remote File Injection attempt in ARGS (admin.php)',deny,status:403"
SecRule MATCHED_VARS "!@rx ://%{SERVER_NAME}/"