You have always been able to define your own custom arrowheads. Typically it would look something like:
<!–[if gte mso 10]><>
/* Style Definitions */
table.MsoNormalTable
{mso-style-name:“Table Normal”;
mso-tstyle-rowband-size:0;
mso-tstyle-colband-size:0;
mso-style-noshow:yes;
mso-style-priority:99;
mso-style-qformat:yes;
mso-style-parent:"";
mso-padding-alt:0in 5.4pt 0in 5.4pt;
mso-para-margin-top:0in;
mso-para-margin-right:0in;
mso-para-margin-bottom:10.0pt;
mso-para-margin-left:0in;
line-height:115%;
mso-pagination:widow-orphan;
font-size:11.0pt;
font-family:“Calibri”,“sans-serif”;
mso-ascii-font-family:Calibri;
mso-ascii-theme-font:minor-latin;
mso-fareast-font-family:“Times New Roman”;
mso-fareast-theme-font:minor-fareast;
mso-hansi-font-family:Calibri;
mso-hansi-theme-font:minor-latin;
mso-bidi-font-family:“Times New Roman”;
mso-bidi-theme-font:minor-bidi;}
<![endif]–>
<go:LinkPanel . . . >
. . . <Polygon Fill="Black" Points="8 4 0 8 2 4 0 0" go:LinkPanel.Alignment="MiddleRight" go:LinkPanel.Index="-1" go:LinkPanel.Orientation="Along" /> </go:LinkPanel>But for version 1.2 we have defined a bunch of common arrowhead shapes, so that you don’t have to. They are enumerated by the Arrowhead type. Now you can get the same effect as above with:
<!–[if gte mso 10]><>
/* Style Definitions */
table.MsoNormalTable
{mso-style-name:“Table Normal”;
mso-tstyle-rowband-size:0;
mso-tstyle-colband-size:0;
mso-style-noshow:yes;
mso-style-priority:99;
mso-style-qformat:yes;
mso-style-parent:"";
mso-padding-alt:0in 5.4pt 0in 5.4pt;
mso-para-margin-top:0in;
mso-para-margin-right:0in;
mso-para-margin-bottom:10.0pt;
mso-para-margin-left:0in;
line-height:115%;
mso-pagination:widow-orphan;
font-size:11.0pt;
font-family:“Calibri”,“sans-serif”;
mso-ascii-font-family:Calibri;
mso-ascii-theme-font:minor-latin;
mso-fareast-font-family:“Times New Roman”;
mso-fareast-theme-font:minor-fareast;
mso-hansi-font-family:Calibri;
mso-hansi-theme-font:minor-latin;
mso-bidi-font-family:“Times New Roman”;
mso-bidi-theme-font:minor-bidi;}
<![endif]–>
<go:LinkPanel . . . >
. . . <<span style=“font-size: 10pt; line-height: 115%; font-family: “Courier New”; color: rgb(163, 21, 21);”>Path<span style=“font-size: 10pt; line-height: 115%; font-family: “Courier New”; color: red;”> Fill<span style=“font-size: 10pt; line-height: 115%; font-family: “Courier New”; color: blue;”>=“Black”<span style=“font-size: 10pt; line-height: 115%; font-family: “Courier New”; color: red;”> go<span style=“font-size: 10pt; line-height: 115%; font-family: “Courier New”; color: blue;”>:<span style=“font-size: 10pt; line-height: 115%; font-family: “Courier New”; color: red;”>LinkPanel.ToArrow<span style=“font-size: 10pt; line-height: 115%; font-family: “Courier New”; color: blue;”>=“Standard”/><span style=“font-size: 10pt; font-family: “Courier New”; color: rgb(163, 21, 21);”>
<span style=“font-size: 10pt; font-family: “Courier New”; color: blue;”></<span style=“font-size: 10pt; font-family: “Courier New”; color: rgb(163, 21, 21);”>go<span style=“font-size: 10pt; font-family: “Courier New”; color: blue;”>:<span style=“font-size: 10pt; font-family: “Courier New”; color: rgb(163, 21, 21);”>LinkPanel<span style=“font-size: 10pt; font-family: “Courier New”; color: blue;”>>
All of the predefined arrowheads are shown in the new Arrowheads sample. Here’s a screenshot: